Plotchart - Plotchart

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# Plotchart(n) 2.3.5 tklib "Plotchart"

## Name

Plotchart - Simple plotting and charting package

## Synopsis

- package require Tcl ?8.5?
- package require Tk ?8.5?
- package require Plotchart ?2.4.0?

- ::Plotchart::createXYPlot w xaxis yaxis args
- ::Plotchart::createStripchart w xaxis yaxis args
- ::Plotchart::createTXPlot w timeaxis xaxis args
- ::Plotchart::createXLogYPlot w xaxis yaxis args
- ::Plotchart::createLogXYPlot w xaxis yaxis args
- ::Plotchart::createLogXLogYPlot w xaxis yaxis args
- ::Plotchart::createPolarPlot w radius_data args
- ::Plotchart::createWindrose w radius_data sectors
- ::Plotchart::createIsometricPlot w xaxis yaxis stepsize
- ::Plotchart::createHistogram w xaxis yaxis args
- ::Plotchart::create3DPlot w xaxis yaxis zaxis args
- ::Plotchart::create3DRibbonPlot w yaxis zaxis
- ::Plotchart::createPiechart w
- ::Plotchart::createSpiralPie w
- ::Plotchart::createRadialchart w names scale style
- ::Plotchart::createBarchart w xlabels yaxis noseries args
- ::Plotchart::createHorizontalBarchart w xaxis ylabel noseries
- ::Plotchart::create3DBarchart w yaxis nobars
- ::Plotchart::create3DRibbonChart w names yaxis zaxis
- ::Plotchart::createBoxplot w xdata ydata orientation
- ::Plotchart::createTimechart w time_begin time_end args
- ::Plotchart::createGanttchart w time_begin time_end args
- ::Plotchart::createRightAxis w_or_plot yaxis
- ::Plotchart::createTableChart w columns ?widths?
- ::Plotchart::createTernaryDiagram w args
- ::Plotchart::createNormalPlot w xscale args
- ::Plotchart::createStatusTimeline w xaxis ylabel args
- $anyplot title text position
- $anyplot subtitle text
- $anyplot canvas
- $anyplot saveplot filename args
- $anyplot xtext text
- $anyplot ytext text
- $anyplot vtext text
- $anyplot xsubtext text
- $anyplot ysubtext text
- $anyplot vsubtext text
- $anyplot xconfig -option value ...
- $anyplot yconfig -option value ...
- $anyplot background part colour_or_image dir ?brightness?
- $anyplot xticklines colour ?dash?
- $anyplot yticklines colour ?dash?
- $anyplot legend series text ?spacing?
- $anyplot removefromlegend series
- $anyplot legendconfig -option value ...
- $anyplot balloon x y text dir
- $anyplot balloonconfig args
- $anyplot plaintext x y text dir
- $anyplot plaintextconfig args
- $anyplot object itemtype series args
- $anyplot deletedata
- $xyplot plot series xcrd ycrd
- $normalplot plot series mean stdev data
- $normalplot diagonal
- $xyplot plotlist series xlist ylist every
- $xyplot region series xlist ylist
- $xyplot minmax series xcrd ymin ymax
- $histogram plotcumulative series xcrd ycrd
- $xyplot trend series xcrd ycrd
- $xyplot rchart series xcrd ycrd
- $xyplot interval series xcrd ymin ymax ?ycentr?
- $xyplot box-and-whiskers series xcrd ycrd
- $xyplot vector series xcrd ycrd ucmp vcmp
- $xyplot vectorconfig series -option value ...
- $xyplot dot series xcrd ycrd value
- $xyplot dotconfig series -option value ...
- $xyplot contourlines xcrd ycrd values ?classes?
- $xyplot contourlinesfunctionvalues xvec yvec valuesmat ?classes?
- $xyplot contourfill xcrd ycrd values ?classes?
- $xyplot contourbox xcrd ycrd values ?classes?
- $xyplot colorMap colours
- $xyplot legendisolines values classes
- $xyplot legendshades values classes
- $xyplot grid xcrd ycrd
- $xyplot xband ymin ymax
- $xyplot yband xmin xmax
- $xyplot labeldot x y text orient
- $polarplot plot series radius angle
- $windrose plot data colour
- $plot3d plotfunc function
- $plot3d plotfuncont function contours
- $plot3d gridsize nxcells nycells
- $plot3d plotdata data
- $plot3d interpolatedata data contours
- $plot3d colour fill border
- $plot3d ribbon yzpairs
- $plot3d plot yzpairs
- $xyplot dataconfig series -option value ...
- $pie plot data
- $pie colours colour1 colour2 ...
- $pie explode segment
- $radial plot data colour thickness
- $pie colours colour1 colour2 ...
- $barchart plot series ydata colour ?dir? ?brightness?
- $barchart config -option value ...
- $barchart plot series xdata colour ?dir? ?brightness?
- $barchart config -option value ...
- $barchart plot label yvalue colour
- $barchart config -option value ...
- $ribbon line xypairs colour
- $ribbon area xypairs colour
- $boxplot plot series label values
- $timechart period text time_begin time_end colour
- $timechart addperiod time_begin time_end colour
- $timechart milestone text time colour
- $timechart addmilestone time colour
- $timechart vertline text time colour
- $timechart hscroll scrollbar
- $timechart vscroll scrollbar
- $ganttchart task text time_begin time_end completed
- $ganttchart milestone text time colour
- $ganttchart vertline text time
- $ganttchart connect from to
- $ganttchart summary text args
- $ganttchart color keyword newcolor
- $ganttchart font keyword newfont
- $ganttchart hscroll scrollbar
- $ganttchart vscroll scrollbar
- $isoplot plot rectangle x1 y1 x2 y2 colour
- $isoplot plot filled-rectangle x1 y1 x2 y2 colour
- $isoplot plot circle xc yc radius colour
- $isoplot plot filled-circle xc yc radius colour
- $table row items
- $table separator
- $table formatcommand procname
- $table cellconfigure args
- $ternary plot series xcrd ycrd zcrd text dir
- $ternary line series coords
- $ternary fill series coords
- $ternary text xtext ytext ztext
- $ternary ticklines colour
- $timeline plot series item start stop color
- $timeline vertline text time args
- ::Plotchart::viewPort w pxmin pymin pxmax pymax
- ::Plotchart::worldCoordinates w xmin ymin xmax ymax
- ::Plotchart::world3DCoordinates w xmin ymin zmin xmax ymax zmax
- ::Plotchart::coordsToPixel w x y
- ::Plotchart::coords3DToPixel w x y z
- ::Plotchart::polarCoordinates w radmax
- ::Plotchart::polarToPixel w rad phi
- ::Plotchart::pixelToCoords w x y
- ::Plotchart::pixelToIndex w x y
- ::Plotchart::determineScale xmin xmax inverted
- ::Plotchart::determineScaleFromList values inverted
- ::Plotchart::plotconfig charttype component property value
- ::Plotchart::plotstyle subcmd style args
- ::Plotchart::eraseplot anyplot
- ::Plotchart::createTargetDiagram w limits scale
- $target plot series xvalues yvalues
- ::Plotchart::createPerformanceProfile w max
- $performance plot series_and_data_pairs
- ::Plotchart::plotmethod charttype methodname plotproc
- ::Plotchart::plotpack w dir args
- $anyplot bindplot event command args
- $anyplot bindlast series event command

## Description

Plotchart is a Tcl-only package that focuses on the easy creation of xy-plots, barcharts and other common types of graphical presentations. The emphasis is on ease of use, rather than flexibility. The procedures that create a plot use the entire canvas window, making the layout of the plot completely automatic.

This results in the creation of an xy-plot in, say, ten lines of code:

        package require Plotchart
        canvas .c -background white -width 400 -height 200
        pack   .c -fill both
        #
        # Create the plot with its x- and y-axes
        #
        set s [::Plotchart::createXYPlot .c {0.0 100.0 10.0} {0.0 100.0 20.0}]
        foreach {x y} {0.0 32.0 10.0 50.0 25.0 60.0 78.0 11.0 } {
            $s plot series1 $x $y
        }
        $s title "Data series"

A drawback of the package might be that it does not do any data management. So if the canvas that holds the plot is to be resized, the whole plot must be redrawn. The advantage, though, is that it offers a number of plot and chart types:

- XY-plots like the one shown above with any number of data series.

- Stripcharts, a kind of XY-plots where the horizontal axis is adjusted automatically. The result is a kind of sliding window on the data series.

- Polar plots, where the coordinates are polar instead of cartesian.

- Histograms, for plotting statistical information.

- Barcharts, piecharts, Gantt charts, time charts.

- Isometric plots, where the scale of the coordinates in the two directions is always the same, i.e. a circle in world coordinates appears as a circle on the screen.

  You can zoom in and out, as well as pan with these plots (Note: this works best if no axes are drawn, the zooming and panning routines do not distinguish the axes), using the mouse buttons with the control key and the arrow keys with the control key.

- Piecharts, with automatic scaling to indicate the proportions.

- Barcharts, with either vertical or horizontal bars, stacked bars or bars side by side.

- Timecharts, where bars indicate a time period and milestones or other important moments in time are represented by triangles.

- 3D plots (both for displaying surfaces and 3D bars)

With version 1.5 a new command has been introduced: plotconfig, which can be used to configure the plot options for particular types of plots and charts (cf. CONFIGURATION OPTIONS AND OTHER COMMANDS) With version 1.8.3 several new features were introduced, which allow more interactivity (cf. INTERACTIVE USE) With version 2.0 it has become possible to put several plots or charts in one canvas.

## PLOT CREATION COMMANDS

You create the plot or chart with one single command and then fill the plot with data:

::Plotchart::createXYPlot w xaxis yaxis args

  Create a new xy-plot (configuration type: xyplot).

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list xaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the x-axis, in this order. For an inverted axis, where the maximum appears on the left-hand side, use: maximum, minimum and a negative stepsize.

  list yaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the y-axis, in this order. For an inverted axis, where the maximum appears at the bottom, use: maximum, minimum and a negative stepsize.

  list args (in)

    Zero or more options that influence the appearance of the plot:

    - -xlabels {labels}: Custom labels for the x-axis. If the labels are numeric, they are positioned according to the given scale, otherwise they are positioned with equal distance, based on the number of labels. Note: this only works if the stepsize of the xaxis argument is the empty string.

    - -ylabels {labels}: Similarly, custom labels for the y-axis.

    - -box {measures}: See ARRANGING MULTIPLE PLOTS IN A CANVAS

    - -axesbox {measures}: See ARRANGING MULTIPLE PLOTS IN A CANVAS

    - -timeformat format: See USING DATE/TIME LABELS

    - -gmt 0/1: See USING DATE/TIME LABELS

    - -axestozero: Draw the axes at the origin (1), or at the sides of the plot area (0, default). This option is implemented for XY plots only.

    - -isometric: Rescale the axes, so that a square in the coordinates appears as a square on the screen (1), or use the given extremes (0, default). This option is implemented for XY plots only.

::Plotchart::createStripchart w xaxis yaxis args

  Create a new strip chart (configuration type: stripchart). The only difference to a regular XY plot is that the x-axis will be automatically adjusted when the x-coordinate of a new point exceeds the maximum.

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list xaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the x-axis, in this order. Note that an inverted x-axis is not supported for this type of plot.

  list yaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the y-axis, in this order. For an inverted axis, where the maximum appears at the bottom, use: maximum, minimum and a negative stepsize.

  list args (in)

    Zero or more options - see the XY-plot for more information.

::Plotchart::createTXPlot w timeaxis xaxis args

  Create a new time-x-plot (configuration type: txplot). The horizontal axis represents the date/time of the data and the vertical axis the values themselves.

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list timeaxis (in)

    A 3-element list containing the minimum and maximum date/time to be shown and the stepsize (in days) for the time-axis, in this order. Note that an inverted time-axis is not supported.

  list xaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the vertical axis, in this order. For an inverted axis, where the maximum appears at the bottom, use: maximum, minimum and a negative stepsize.

  list args (in)

    Zero or more options - see the XY-plot for more information.

::Plotchart::createXLogYPlot w xaxis yaxis args

  Create a new xy-plot where the y-axis has a logarithmic scale (configuration type: xlogyplot).

  The data should be given as for a linear scale, as the logarithmic transformation is taken of internally.

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list xaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the x-axis, in this order. For an inverted axis, where the maximum appears on the left-hand side, use: maximum, minimum and a negative stepsize.

  list yaxis (in)

    A 2-element list containing minimum and maximum for the y-axis, in this order. Note that an inverted logarithmic axis is not supported.

  list args (in)

    Zero or more options - see the XY-plot for more information.

::Plotchart::createLogXYPlot w xaxis yaxis args

  Create a new xy-plot where the x-axis has a logarithmic scale (configuration type: logxyplot).

  The data should be given as for a linear scale, as the logarithmic transformation is taken of internally.

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list xaxis (in)

    A 2-element list containing minimum and maximum for the x-axis, in this order. Note that an inverted logarithmic axis is not supported.

  list yaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the y-axis, in this order. For an inverted axis, where the maximum appears on the left-hand side, use: maximum, minimum and a negative stepsize.

  list args (in)

    Zero or more options - see the XY-plot for more information.

::Plotchart::createLogXLogYPlot w xaxis yaxis args

  Create a new xy-plot where both the x-axis and the y-axis have a logarithmic scale (configuration type: logxlogyplot).

  The data should be given as for a linear scale, as the logarithmic transformation is taken of internally.

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list xaxis (in)

    A 2-element list containing minimum and maximum for the x-axis, in this order. Note that an inverted logarithmic axis is not supported.

  list yaxis (in)

    A 2-element list containing minimum and maximum for the y-axis, in this order. Note that an inverted logarithmic axis is not supported.

  list args (in)

    Zero or more options - see the XY-plot for more information.

::Plotchart::createPolarPlot w radius_data args

  Create a new polar plot (configuration type: polarplot).

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list radius_data (in)

    A 2-element list containing maximum radius and stepsize for the radial axis, in this order.

  list args (in)

    Zero or more options - see the XY-plot for more information.

::Plotchart::createWindrose w radius_data sectors

  Create a new windrose diagram. The diagram will consist of concentric circles as defined by the radius_data argument and a number of sectors (given by the sectors argument). The sectors are drawn in the "nautical" convention, that is: the first is located at the positive y-axis, the second is to the right and so on in a clockwise direction.

  widget w (in)

    Name of the existing canvas widget to hold the diagram

  list radius_data (in)

    A 2-element list, the first element is the maximum radius, the second is the step to be used for the circles.

  int sectors

    Number of sectors to use (defaults to 16).

::Plotchart::createIsometricPlot w xaxis yaxis stepsize

  Create a new isometric plot, where the vertical and the horizontal coordinates are scaled so that a circle will truly appear as a circle (configuration type: isometric).

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list xaxis (in)

    A 2-element list containing minimum, and maximum for the x-axis, in this order.

  list yaxis (in)

    A 2-element list containing minimum, and maximum for the y-axis, in this order.

  float|noaxes stepsize (in)

    Either the stepsize used by both axes or the keyword noaxes to signal the plot that it should use the full area of the widget, to not draw any of the axes.

::Plotchart::createHistogram w xaxis yaxis args

  Create a new histogram (configuration type: histogram).

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list xaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the x-axis, in this order.

  list yaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the y-axis, in this order.

  list args (in)

    Zero or more options - see the XY-plot for more information.

::Plotchart::create3DPlot w xaxis yaxis zaxis args

  Create a new 3D plot.

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list xaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the x-axis, in this order.

  list yaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the y-axis, in this order.

  list zaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the z-axis, in this order.

  list args (in)

    Optional list of options (keyword-value pairs). Currently supported: -xlabels to set the labels for the x-axis.

::Plotchart::create3DRibbonPlot w yaxis zaxis

  Create a new 3D ribbon plot. It is a simplification of the full 3D plot and allows for the drawing of a ribbon only (the x-axis is dropped).

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list yaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the y-axis, in this order.

  list zaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the z-axis, in this order.

::Plotchart::createPiechart w

  Create a new piechart (configuration type: piechart).

  widget w (in)

    Name of the existing canvas widget to hold the plot.

::Plotchart::createSpiralPie w

  Create a new "spiral pie" (configuration type: spiralpie), a variation on the ordinary piechart. The value is used to scale the radius, rather than the angle. By default the data are sorted.

  widget w (in)

    Name of the existing canvas widget to hold the plot.

::Plotchart::createRadialchart w names scale style

  Create a new radial chart (the data are drawn as a line connecting the spokes of the diagram) (configuration type: radialchart).

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list names (in)

    Names for the spokes.

  float scale (in)

    Scale value to determine the position of the data along the spokes.

  string style (in)

    Style of the chart (optional). One of:

    - lines - the default: draw the data as independent polylines.

    - cumulative - draw the data as polylines where the data are accumulated.

    - filled - draw the data as filled polygons where the data are accumulated

::Plotchart::createBarchart w xlabels yaxis noseries args

  Create a new barchart with vertical bars (configuration type: vertbars). The horizontal axis will display the labels contained in the argument xlabels. The number of series given by noseries determines both the width of the bars, and the way the series will be drawn.

  If the keyword stacked was specified the series will be drawn stacked on top of each other. Otherwise each series that is drawn will be drawn shifted to the right.

  The number of series determines the width of the bars, so that there is space of that number of bars. If you use a floating-point number, like 2.2, instead of an integer, like 2, a small gap between the sets of bars will be drawn - the width depends on the fractional part.

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list xlabels (in)

    List of labels for the x-axis. Its length also determines the number of bars that will be plotted per series.

  list yaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the y-axis, in this order.

  int|stacked noseries (in)

    The number of data series that will be plotted. This has to be an integer number greater than zero (if stacked is not used).

  string args (in)

    One or more key-value pairs defining the options. Specific to barcharts: -xlabelangle value, the angle under which the labels should be drawn. This defaults to 0 - horizontal text. This option is especially useful if you have fairly long labels.

::Plotchart::createHorizontalBarchart w xaxis ylabel noseries

  Create a new barchart with horizontal bars (configuration type: horizbars). The vertical axis will display the labels contained in the argument ylabels. The number of series given by noseries determines both the width of the bars, and the way the series will be drawn.

  If the keyword stacked was specified the series will be drawn stacked from left to right. Otherwise each series that is drawn will be drawn shifted upward.

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list xaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the x-axis, in this order.

  list ylabels (in)

    List of labels for the y-axis. Its length also determines the number of bars that will be plotted per series.

  int|stacked noseries (in)

    The number of data series that will be plotted. This has to be an integer number greater than zero (if stacked is not used).

::Plotchart::create3DBarchart w yaxis nobars

  Create a new barchart with 3D vertical bars (configuration type: 3dbars). The horizontal axis will display the labels per bar. The number of bars given by nobars determines the position and the width of the bars. The colours can be varied per bar. (This type of chart was inspired by the Wiki page on 3D bars by Richard Suchenwirth.)

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list yaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the y-axis, in this order.

  int nobars (in)

    The number of bars that will be plotted.

::Plotchart::create3DRibbonChart w names yaxis zaxis

  Create a new "ribbon chart" (configuration type: 3dribbon). This is a chart where the data series are represented as ribbons in a three-dimensional axis system. Along the x-axis (which is "into" the screen) the names are plotted, each representing a single series. The first plot command draws the furthest series, the second draws the series in front of that and so on.

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  widget w (in)

    Names of the series, plotted as labels along the x-axis

  list yaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the y-axis (drawn horizontally!), in this order.

  list zaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the z-axis (drawn vertically), in this order.

  int nobars (in)

    The number of bars that will be plotted.

::Plotchart::createBoxplot w xdata ydata orientation

  Create a new boxplot with horizontal or vertical boxes (box-and-whiskers) (configuration type: boxplot). Depending on the orientation the x- or y-axis is drawn with labels. The boxes are drawn based on the raw data (see the plot subcommand for this type of plot).

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list xdata (in)

    This is either a 3-element list containing minimum, maximum and stepsize for the x-axis, in this order (when orientation is horizontal), or a list of labels for the x-axis (when orientation is vertical). The length of the label list also determines the number of boxes that can be plotted. The labels are also used in the plot subcommand.

  list ydata (in)

    This is either a 3-element list containing minimum, maximum and stepsize for the y-axis, in this order (when orientation is vertical), or a list of labels for the y-axis (when orientation is horizontal). The length of the label list also determines the number of boxes that can be plotted. The labels are also used in the plot subcommand.

  string orientation (in)

    If given, "horizontal" or "vertical" determines the orientation of the boxes. This optional value (default: horizontal) also determines the interpretation of the xdata and ydata arguments.

::Plotchart::createTimechart w time_begin time_end args

  Create a new timechart (configuration type: timechart). The time axis (= x-axis) goes from time_begin to time_end, and the vertical spacing is determined by the number of items to plot.

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  string time_begin (in)

    The start time given in a form that is recognised by the clock scan command (e.g. "1 january 2004").

  string time_end (in)

    The end time given in a form that is recognised by the clock scan command (e.g. "1 january 2004").

  arguments args (in)

    The remaining arguments can be:

    - The expected/maximum number of items. This determines the vertical spacing. (If given, it must be the first argument after "time_end"

    - The keyword -barheight and the number of pixels per bar. This is an alternative method to determine the vertical spacing.

    - The keyword -ylabelwidth and the number of pixels to reserve for the labels at the y-axis.

::Plotchart::createGanttchart w time_begin time_end args

  Create a new Gantt chart (configuration type: ganttchart). The time axis (= x-axis) goes from time_begin to time_end, and the vertical spacing is determined by the number of items to plot. Via the specific commands you can then add tasks and connections between the tasks.

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  string time_begin (in)

    The start time given in a form that is recognised by the clock scan command (e.g. "1 january 2004").

  string time_end (in)

    The end time given in a form that is recognised by the clock scan command (e.g. "1 january 2004").

  arguments args (in)

    The remaining arguments can be:

    - The expected/maximum number of items. This determines the vertical spacing. (If given this way, it must be the first argument after "time_end")

    - The expected/maximum width of the descriptive text (roughly in characters, for the actual space reserved for the text, it is assumed that a character is about ten pixels wide). Defaults to 20. (If given this way, it must be the second argument after "time_end").

    - The keyword -barheight and the number of pixels per bar. This is an alternative method to determine the vertical spacing.

    - The keyword -ylabelwidth and the number of pixels to reserve for the labels at the y-axis.

::Plotchart::createRightAxis w_or_plot yaxis

  Create a plot command that will use a right axis instead of the left axis (configuration type: inherited from the existing plot). The canvas widget must already contain an ordinary plot, as the horizontal axis and other properties are reused. Preferably use the plot command, as with multiple plots in a canvas (also when redefining an existing plot!), the wrong geometry might be used.

  To plot data using the right axis, use this new command, to plot data using the left axis, use the original plot command.

  widget w_or_plot (in)

    Name of the existing canvas widget to hold the plot or preferably the plot command for the plot with the left axis.

  list yaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the y-axis, in this order.

::Plotchart::createTableChart w columns ?widths?

  Create a command to draw a table. You can use a variety of commands to draw the actual rows of the table, but the number of columns is fixed. (See TABLE CHARTS for an example)

  widget w (in)

    Name of the canvas widget to hold the table.

  list columns (in)

    The headers of the columns in the table. The number of elements determines the number of columns.

  list widths (in)

    If given, either a single value, the width in pixels for all columns or for each column the width of that column. If not given, the table is spread out over the width of the canvas (minus the margins).

::Plotchart::createTernaryDiagram w args

  Create a command to draw a ternary diagram (configuration type: ternary). You can draw individual (labelled) data points in the diagram, lines and filled polygons.

  widget w (in)

    Name of the canvas widget to hold the ternary diagram.

  list args (in)

    Zero or more option-value pairs to influence the position and the appearance of the diagram. In addition to the positioning options (-box and -axesbox) the diagram supports: -fractions yes/no, to display numbers 0 to 1 instead of 0 to 100% and -steps number to influence the number of labels along the three sides.

::Plotchart::createNormalPlot w xscale args

  Create a command to draw a normal plot - useful to investigate whether a data set is normally distributed or not. In that case the data will fall on or near the diagonal. As such, it is a specialised plotting procedure.

  The details of the plotting procedure have been adopted from the qqnorm in the "R" stats package and described on Wikipedia.

  As the implementation of this plot type relies on the math::statistics package, it is only available if that package can be loaded.

  widget w (in)

    Name of the canvas widget to hold the normal plot.

  list xscale (in)

    A 3-element list containing minimum, maximum and stepsize for the x-axis in this order. The scaling of the y-axis is determined from that. Important: the scale is to be given in terms of the normalised data, that is: 0 represents the mean of the data, 1 one standard deviation away from the mean etc.

  list args (in)

    Zero or more option-value pairs to influence the position and the appearance of the plot - see the XY-plot for more details.

::Plotchart::createStatusTimeline w xaxis ylabel args

  Create a command to draw a so-called status timeline. Its layout is similar to a horizontal barchart, but the bars are drawn in different colours, each representing the status of the item as it varies over time (the horizontal axis).

  widget w (in)

    Name of the canvas widget to hold the ternary diagram.

  list xaxis (in)

    A 3-element list containing minimum, maximum and stepsize for the x-axis, in this order.

  list ylabels (in)

    List of labels for the y-axis. Its length also determines the number of bars that will be plotted per series.

  list args (in)

    Zero or more option-value pairs to influence the position and the appearance of the diagram. In addition to the positioning options (-box and -axesbox) the diagram supports: -xaxis yes/no, to turn displaying the numeric labels on or off.

## PLOT METHODS

Each of the creation commands explained in the last section returns the name of a new object command that can be used to manipulate the plot or chart. The subcommands available to a chart command depend on the type of the chart.

General subcommands for all types of charts. \$anyplot is the command returned by the creation command:

$anyplot title text position

  Specify the title of the whole chart.

  string text (in)

    The text of the title to be drawn.

  string position (in)

    The position of the title. The default position is "center", but you can alternatively use "left" or "right". You can use multiple titles with different positions.

$anyplot subtitle text

  Specify the subtitle of the whole chart.

  string text (in)

    The text of the subtitle to be drawn.

$anyplot canvas

  Return the name of the canvas (or the alias if you use more than one plot within a canvas). Use this value for the coordinate transformations.

$anyplot saveplot filename args

  Draws the plot into a file, using PostScript.

  string filename (in)

    Contain the path name of the file to write the plot to.

  list args (in)

    If the standard PostScript output is used, the option -plotregion can be specifed to save the whole plot (value: bbox) regardless of what is visible in the window. The default (value: window) is to only plot the visible part of the plot.

    Optionally you can specify the option -format "some picture format" to store the plot in a different file than a PostScript file. This, however, relies on the Img package to do the actual job.

    Note: Because the window holding the plot must be fully visible before Img can successfully grab it, it is raised first. On some systems, for instance Linux with KDE, raising a window is not done automatically, but instead you need to click on the window in the task bar. Similar things happen on Windows XP.

    There seems to be something wrong under some circumstances, so instead of waiting for the visibility of the window, the procedure simply waits two seconds. It is not ideal, but it seems to work better.

$anyplot xtext text

  Specify the title of the (horizontal) x-axis, for those plots that have a straight x-axis.

  string text (in)

    The text of the x-axis label to be drawn.

$anyplot ytext text

  Specify the title of the (horizontal) y-axis, for those plots that have a straight y-axis.

  string text (in)

    The text of the y-axis label to be drawn.

$anyplot vtext text

  Draw a vertical label to the y-axis. Note: this requires Tk 8.6 or later, for older versions it does nothing.

  string text (in)

    Text to drawn to the y-axis

$anyplot xsubtext text

  Specify the subtext of the (horizontal) x-axis, for those plots that have a straight x-axis. This text is drawn below the primary text.

  Since this involves positioning the primary text and setting margins, you need to set the option "usesubtext" for the bottom axis via the plotstyle command. The relevant options are: usesubtext, subtextcolor and subtextfont.

  string text (in)

    The secondary text of the x-axis label to be drawn.

$anyplot ysubtext text

  Specify the subtext of the (vertical) y-axis, for those plots that have a straight y-axis. This text is drawn below the primary text, for both axes on the left and the right.

  Since this involves positioning the primary text and setting margins, you need to set the option "usesubtext" for the left or right axis via the plotstyle command. The relevant options are: usesubtext, subtextcolor and subtextfont.

  string text (in)

    The secondary text of the y-axis label to be drawn.

$anyplot vsubtext text

  Specify the subtext of the (vertical) y-axis, for those plots that have a straight y-axis. This text is drawn to the right of the primary text, for both axes on the left and the right.

  Since this involves positioning the primary text and setting margins, you need to set the option "usesubtext" for the left or right axis via the plotstyle command. The relevant options are: usevsubtext, vsubtextcolor and vsubtextfont. (Note the "v" to distinguish this option from the text at the top of a vertical axis that is drawn via $anyplot ytext or $anyplot ysubtext.)

  string text (in)

    The secondary (vertical) text of the y-axis label to be drawn.

$anyplot xconfig -option value ...

  Set one or more configuration parameters for the x-axis. The following options are supported:

  format fmt

    The format for the numbers along the axis.

  ticklength length

    The length of the tickmarks (in pixels).

  ticklines boolean

    Whether to draw ticklines (true) or not (false).

  scale scale_data

    New scale data for the axis, i.e. a 3-element list containing minimum, maximum and stepsize for the axis, in this order.

    Beware: Setting this option will clear all data from the plot.

$anyplot yconfig -option value ...

  Set one or more configuration parameters for the y-axis. This method accepts the same options and values as the method xconfig.

$anyplot background part colour_or_image dir ?brightness?

  Set the background of a part of the plot

  string part

    Which part of the plot: "axes" for the axes area and "plot" for the inner part. The interpretation depends on the type of plot. Two further possibilities are:

    - image, in which case a predefined image is loaded into the background of the plot.

    - gradient, in which case the background is coloured in different shades of the given colour. The "dir" argument specifies the direction in which the colour gets whiter.

  string colour_or_image

    Colour for that part or the name of the image if "part" is "image"

  string dir

    The direction of the gradient. One of: top-down, bottom-up, left-right or right-left.

  string brightness

    Indicates whether the colour should become brighter (bright) or darker (dark). Defaults to bright

$anyplot xticklines colour ?dash?

  Draw vertical ticklines at each tick location

  string colour

    Colour of the lines. Specifying an empty colour ("") removes them again. Defaults to "black"

  string dash

    Optional argument to specify the dash pattern for the lines. Defaults to "lines" Possible values: lines, dots1, dots2, dots3, dots4, dots5. The actual effect depends on the platform.

$anyplot yticklines colour ?dash?

  Draw horizontal ticklines at each tick location

  string colour

    Colour of the lines. Specifying an empty colour ("") removes them again Defaults to "black"

  string dash

    Optional argument to specify the dash pattern for the lines. Defaults to "lines" Possible values: lines, dots1, dots2, dots3, dots4, dots5. The actual effect depends on the platform.

$anyplot legend series text ?spacing?

  Add an entry to the legend. The series determines which graphical symbol is to be used. (As a side effect the legend is actually drawn.)

  string series

    Name of the data series. This determines the colour of the line and the symbol (if any) that will be drawn.

  string text

    Text to be drawn next to the line/symbol.

  integer spacing

    Optional argument to specify the vertical spacing between the entries (in pixels). (Note that this spacing will be reused later.)

$anyplot removefromlegend series

  Remove an entry for a series from the legend and redraw it.

  string series

    Name of the data series to be removed.

$anyplot legendconfig -option value ...

  Set one or more options for the legend. The legend is drawn as a rectangle with text and graphics inside.

  background colour

    Set the colour of the background (the default colour is white). Set to the empty string for a transparant legend.

  border colour

    Set the colour of the border (the default colour is black). Set to the empty string if you do not want a border.

  canvas c

    Draw the legend in a different canvas widget. This gives you the freedom to position the legend outside the actual plot.

  font font

    Set the font used to draw the text next to the symbol.

  legendtype type

    Override the type of the legend, that is pre-defined for the current type of plot. May be one of: rectangle or line.

  position corner

    Set the position of the legend. May be one of: top-left, top-right, bottom-left or bottom-right. (Default value is top-right.)

  spacing pixels

    Set the vertical spacing between entries in the legend (in pixels). bottom-left or bottom-right. (Default value is 10 pixels.)

$anyplot balloon x y text dir

  Add balloon text to the plot (except for 3D plots). The arrow will point to the given x- and y-coordinates. For xy-graphs and such, the coordinates are directly related to the axes; for vertical barcharts the x-coordinate is measured as the number of bars minus 1 and similar for horizontal barcharts.

  float x

    X-coordinate of the point that the arrow of the balloon will point to.

  float y

    Y-coordinate of the point that the arrow of the balloon will point to.

  string text

    Text to be drawn in the balloon.

  string dir

    Direction of the arrow, one of: north, north-east, east, south-east, south, south-west, west or north-west.

$anyplot balloonconfig args

  Configure the balloon text for the plot. The new settings will be used for the next balloon text.

  font fontname

    Font to be used for the text

  justify left|center|right

    Way to justify multiline text

  textcolour colour

    Colour for the text (synonym: textcolor)

  background colour

    Background colour for the balloon

  outline colour

    Colour of the outline of the balloon

  margin value

    Margin around the text (in pixels)

  rimwidth value

    Width of the outline of the balloon (in pixels)

  arrowsize value

    Length factor for the arrow (in pixels)

$anyplot plaintext x y text dir

  Add plain text to the plot (except for 3D plots). The text is positioned at the given x- and y-coordinates. For xy-graphs and such, the coordinates are directly related to the axes; for vertical barcharts the x-coordinate is measured as the number of bars minus 1 and similar for horizontal barcharts.

  float x

    X-coordinate of the text position

  float y

    Y-coordinate of the text position

  string text

    Text to be drawn.

  string dir

    Anchor for the text, one of: north, north-east, east, south-east, south, south-west, west or north-west.

$anyplot plaintextconfig args

  Configure the plain text annotation for the plot. The new settings will be used for the next plain text.

  font fontname

    Font to be used for the text

  justify left|center|right

    Way to justify multiline text

  textcolour colour

    Colour for the text (synonym: textcolor)

$anyplot object itemtype series args

  Draw a canvas item in the plot where the coordinates are scaled using the coordinate system of the plot. In addition to the standard canvas types, it also supports circles, dots and crosses.

  Note: Currently implemented for xy-plots, (vertical and horizontal) barcharts, and piecharts.

  Note: To add an entry in the legend for the object, you can use the dataconfig subcommand with a type "rectangle". This will cause a rectangle to be shown.

  string itemtype (in)

    Name of a standard canvas item or "circle", "dot" or "cross"

  string series (in)

    The data series it belongs to, used for setting the default drawing options

  list args (in)

    List of coordinates and drawing options

$anyplot deletedata

  Remove the lines, symbols and other graphical object associated with the actual data from the plot.

  Note: Currently implemented for xy-plots only

  Note: The existing options for data series and the legend entry are kept as they were.

  Note: Currently there are side effects if the canvas contains more than one plot.

Note: The commands xconfig and yconfig are currently implemented only for XY-plots and only the option -format has any effect.

For xy plots, stripcharts, histograms and time-x-plots:

$xyplot plot series xcrd ycrd

  Add a data point to the plot.

  string series (in)

    Name of the data series the new point belongs to.

  float xcrd (in)

    X-coordinate of the new point. (For time-x plots this must be valid date/time that can be read with the clock scan command).

  float ycrd (in)

    Y-coordinate of the new point.

For normal plots:

$normalplot plot series mean stdev data

  Plot the data set using the given mean and stanard deviation.

  As you give the mean and standard deviation separately, the plot can be used for several data series or for adding to an existing data series.

  string series (in)

    Name of the data series - used to determine the appearance

  float mean (in)

    Assumed mean of the data set.

  float stdev (in)

    Assumed standard deviation of the data set.

  list data (in)

    List of the data comprising the data set

$normalplot diagonal

  Draw a diagonal line, indicating the ideal normally distributed data set.

For xy, x-log y, log-x-y, log-x-log-y plots there is the additional command plotlist, which is useful for plotting a large amount of data:

$xyplot plotlist series xlist ylist every

  Draw a series of data as a whole. If symbols are asked for, draw them only for every Nth data point.

  string series (in)

    Name of the data series the new line belongs to.

  float xlist (in)

    List of X-coordinates for the data series.

  float ycrd (in)

    List of Y-coordinates for the data series.

  int every (in)

    Optional argument stating how often a symbol (if any) should be drawn. If left out, use a simple heuristic: N = sqrt(number of data points).

Other commands for xy, x-log y, log-x-y, log-x-log-y plots are region and minmax to draw filled polygons:

$xyplot region series xlist ylist

  Draw a filled polygon (region). The configuration of the series influences the polygon as follows: -fillcolour is used to fill the polygon, -colour is used for the boundary (set it to {} if no boundary is required and -width determines the width of the boundary.

  string series (in)

    Name of the data series the new region belongs to.

  float xlist (in)

    List of X-coordinates for the region.

  float ycrd (in)

    List of Y-coordinates for the region.

$xyplot minmax series xcrd ymin ymax

  Draw a filled strip representing a minimum and a maximum. The configuration of the series influences the polygon as follows: -fillcolour is used to fill the polygon, -colour is used for the boundary (set it to {} if no boundary is required and -width determines the width of the boundary.

  The arguments ymin and ymax may be empty to get an extra vertex in the strip. If both are empty, a new strip is started. For best results, the x-coordinate should be specified in ascending order.

  string series (in)

    Name of the data series the new min/max strip belongs to.

  float xcrd (in)

    X-coordinate for the strip.

  float ymin (in)

    The minimum y-coordinate for the strip.

  float ymax (in)

    The maximum y-coordinate for the strip.

Note on histograms:

For histograms the x-coordinate that is given is interpreted to be the x-coordinate of the right side of the bar (or line segment). The first bar starts at the y-axis on the left. To completely fill the range of the x-axis, you should draw a bar at the maximum x-coordinate.

For histograms you can also use the plotcumulative command:

$histogram plotcumulative series xcrd ycrd

The arguments mean exactly the same as for the plot command, but the data are accumulated to the previous values.

For xy plots:

$xyplot trend series xcrd ycrd

  Draw or update a trend line using the data given sofar.

  string series (in)

    Name of the data series the trend line belongs to.

  float xcrd (in)

    X-coordinate of the new data point

  float ycrd (in)

    Y-coordinate of the new data point

$xyplot rchart series xcrd ycrd

  Draw data in the same way as the plot method, but with two lines added that indicate the expected range (+/- 3*standard deviation) of the data.

  string series (in)

    Name of the data series the data point belongs to.

  float xcrd (in)

    X-coordinate of the new data point

  float ycrd (in)

    Y-coordinate of the new data point

$xyplot interval series xcrd ymin ymax ?ycentr?

  Add a vertical error interval to the plot. The interval is drawn from ymin to ymax. If the ycentr argument is given, a symbol is drawn at that position.

  string series (in)

    Name of the data series the interval belongs to.

  float xcrd (in)

    X-coordinate of the interval

  float ymin (in)

    Minimum y-coordinate of the interval.

  float ymax (in)

    Maximum y-coordinate of the interval.

  float ycentr (in)

    Y-coordinate to draw the symbol at (optional)

$xyplot box-and-whiskers series xcrd ycrd

  Draw a box and whiskers in the plot. If the argument xcrd is a list of several values and the argument ycrd is a single value, a horizontal box is drawn with the quartiles determined from the list of values contained in xcrd.

  If, instead, the argument ycrd contains a list of several values and the argument xcrd a single value, then a vertical box is drawn and the quartiles are determined from ycrd. (There must be exactly one list of several values. Otherwise an error is reported.)

  The option -boxwidth to the dataconfig command determines the width (or height) of the box (default: 10 pixels).

  The option -whiskers to the dataconfig command determines whether the whiskers are drawn to the extreme values (value: extremes), to 1.5 times the interquartile range (value: IQR or iqr), or not at all (value: none). If the value is 'IQR' (uppercase), then also extreme values will be shown (from 1.5 to 3 times the IQR as dots, above 3 times IQR as stars). If the value is 'iqr' (lowercase) no extreme values will be shown (default value: IQR).

  The option -whiskerwidth to the dataconfig command determines the thickness of the line that draws the whiskers (default: 1 pixel).

  The option -mediancolour to the dataconfig command determines the colour of the line used to draw the median within the box (default: same as -colour).

  The option -medianwidth to the dataconfig command determines the thickness of the line that draws the median within the box (default: 1 pixel).

  string series (in)

    Name of the data series the box-and-whiskers belongs to.

  float xcrd (in)

    X-coordinate of the box or a list of values.

  float ymin (in)

    Y-coordinate of the box or a list of values.

  The box ends at the 1st and 3rd quartile, while the whiskers by default are plotted to span 1.5 IQR (interquartile range) from the 1st and 3rd quartile.

$xyplot vector series xcrd ycrd ucmp vcmp

  Draw a vector in the plot. The vector can be given as either cartesian coordinates or as length/angle, where the angle is in degrees and is interpreted according to the mathematical convention or the nautical. (See the vectorconfig subcommand)

  string series (in)

    Name of the series the vector belongs to. Determines the appearance and interpretation.

  float xcrd (in)

    X-coordinate of the point where the arrow appears

  float ycrd (in)

    Y-coordinate of the point where the arrow appears

  float ucmp (in)

    X-component or the length of the vector

  float ycentr (in)

    Y-component or the angle of the vector

$xyplot vectorconfig series -option value ...

  ] Set the vector drawing options for a particular series

  string series (in)

    Name of the series the vector belongs to.

  The options can be one of the following:

  colour

    The colour of the arrow (default: black; synonym: color)

  scale value

    The scale factor used to convert the length of the arrow into a number of pixels (default: 1.0)

  centred onoff

    Logical value indicating that the xy-coordinates are to be used as the start of the arrow or as the centre (default: 0; synonym: centered)

  type keyword

    Interpretation of the vector components. Can be "cartesian" (default), in which case the x- and y-components are expected, "polar" (the angle 0 coincides with the positive x-axis, 90 coincides with the positive y-axis) or "nautical" (0 is "north" and 90 is "east").

$xyplot dot series xcrd ycrd value

  Draw a dot in the plot. The size and colour is determined by the value and by the options set for the series it belongs to. (See the dotconfig subcommand)

  string series (in)

    Name of the series the dot belongs to. Determines size and colour

  float xcrd (in)

    X-coordinate of the point where the arrow appears

  float ycrd (in)

    Y-coordinate of the point where the arrow appears

  float value (in)

    Value determining size and colour

$xyplot dotconfig series -option value ...

  ] Set the dot drawing options for a particular series

  string series (in)

    Name of the series the dot belongs to.

  The options can be one of the following:

  colour

    The colour of the dot if no scaling is used or the value exceeds the last limit of the classes.

  scale value

    The scale factor used to convert the value into the radius of the dot in pixels (default: 1.0)

  radius value

    The default radius of the dots, used if there is no scaling by value (in pixels; default: 3)

  scalebyvalue onoff

    Determines whether the dots all have the same size or a size depending on the given value (default: on).

  outline onoff

    Draw a black circle around the dot or not (default: on)

  classes list

    Set the limits and the corresponding colours. For instance:

            $xyplot series1 -classes {0 blue 1 green} -colour red

    will cause a blue dot to be drawn for values smaller than 0, a green dot for values larger/equal 0 but lower than 1 and a red dot for values larger/equal 1.

  3deffect onoff

    Show a highlight in the dots, to mimick a 3D effect (default: off)

    If there is no list of classes for the particular series, the dots are scaled by the value.

    You can combine the colouring by value and the scaling by value by setting a list of classes and setting the scalebyvalue option on.

$xyplot contourlines xcrd ycrd values ?classes?

  Draw contour lines for the values given on the grid. The grid is defined by the xcrd and ycrd arguments. The xcrd argument (resp. ycrd) is expected to be a matrix, implemented as a list of lists which gives the x-coordinates (resp. y-coordinates) of the grid cell corners. The function values are given at these corners. The number of rows in xcrd (resp. ycrd) is ny and each row contains nx values so that the total number of values in xcrd (resp. ycrd) is nx * ny. The classes determine which contour lines are drawn. If a value on one of the corners is missing, the contour lines in that cell will not be drawn.

  Entries in the legend are drawn via the legendisolines subcommand.

  list xcrd (in)

    List of lists, each value is an x-coordinate for a grid cell corner

  list ycrd (in)

    List of lists, each value is an y-coordinate for a grid cell corner

  list values (in)

    List of lists, each value is the value at a grid cell corner

  list classes (in)

    List of class values or a list of lists of two elements (each inner list the class value and the colour to be used). If empty or missing, the classes are determined automatically.

    Note: The class values must enclose the whole range of values. Note: The xcrd argument is generally made of nypoints identical rows, while each row of ycrd is made with one single value.

$xyplot contourlinesfunctionvalues xvec yvec valuesmat ?classes?

  Draw contour lines for the values given on the grid. The grid is defined by the xvec and yvec arguments. Here, xvec (resp. yvec) is a list of x-coordinates (resp. y-coordinates). The number of values in xvec (resp. yvec) is the number of points in the x-coordinate (resp. y-coordinate). The function values are given at these corners. The classes determine which contour lines are drawn. If a value on one of the corners is missing, the contour lines in that cell will not be drawn.

  Entries in the legend are drawn via the legendisolines subcommand.

  list xvec (in)

    List of x-coordinates in increasing order.

  list yvec (in)

    List y-coordinates in increasing order.

  list valuesmat (in)

    List of ny lists of nx values, each value is the value at a grid cell corner. The total number of values is valuesmat is nx * ny.

  list classes (in)

    List of class values or a list of lists of two elements (each inner list the class value and the colour to be used). If empty or missing, the classes are determined automatically.

    Note: The class values must enclose the whole range of values.

$xyplot contourfill xcrd ycrd values ?classes?

  Draw filled contours for the values given on the grid. (The use of this method is identical to the "contourlines" method).

  Entries in the legend are drawn via the legendshades subcommand.

$xyplot contourbox xcrd ycrd values ?classes?

  Draw the cells as filled quadrangles. The colour is determined from the average of the values on all four corners.

  Entries in the legend are drawn via the legendshades subcommand.

$xyplot colorMap colours

  Set the colours to be used with the contour methods. The argument is either a predefined colourmap (grey/gray, jet, hot or cool) or a list of colours. When selecting the colours for actually drawing the contours, the given colours will be interpolated (based on the HLS scheme).

  list colours (in)

    List of colour names or colour values or one of the predefined maps:

    - grey or gray: gray colours from dark to light

    - jet: rainbow colours

    - hot: colours from yellow via red to darkred

    - cool: colours from cyan via blue to magenta

$xyplot legendisolines values classes

  Add the contour classes to the legend as coloured lines. The text indicates the values.

  list values (in)

    The list of values as used for the actual drawing. This argument is used only if the list of classes is empty.

  list values (in)

    The list of classes as used for the actual drawing.

$xyplot legendshades values classes

  Add the contour classes to the legend as coloured rectangles. The text indicates the values.

  list values (in)

    The list of values as used for the actual drawing. This argument is used only if the list of classes is empty.

  list values (in)

    The list of classes as used for the actual drawing.

$xyplot grid xcrd ycrd

  Draw the grid cells as lines connecting the (valid) grid points.

  list xcrd (in)

    List of lists, each value is an x-coordinate for a grid cell corner

  list ycrd (in)

    List of lists, each value is an y-coordinate for a grid cell corner

$xyplot xband ymin ymax

  Draw a light grey band in the plot, ranging over the full x-axis. This can be used to indicate a "typical" range for the data.

  float ymin (in)

    Lower bound for the band

  float ymax (in)

    Upper bound for the band

$xyplot yband xmin xmax

  Draw a light grey band in the plot, ranging over the full y-axis. This can be used to indicate a "typical" range for the data.

  float xmin (in)

    Lower bound for the band

  float xmax (in)

    Upper bound for the band

$xyplot labeldot x y text orient

  Draw a label and a symbol in the plot. The label will appear near the symbol. The label will be drawn in grey, so as not to be too conspicuous.

  You can configure the appearance of the symbol by using the data series name "labeldot": $w dataconfig labeldot -colour red -type symbol -symbol dot

  float x (in)

    X-coordinate of the symbol to be drawn

  float y (in)

    Y-coordinate of the symbol to be drawn

  string text (in)

    Text for the label

  string orient (in)

    Optional orientation (one of w, e, n, s) defining the position of the label with respect to the symbol. It defaults to w (so the label appears left of the symbol).

For polar plots:

$polarplot plot series radius angle

  Add a data point to the polar plot.

  string series (in)

    Name of the data series the new point belongs to.

  float radius (in)

    Radial coordinate of the new point.

  float angle (in)

    Angular coordinate of the new point (in degrees).

For wind rose diagrams:

$windrose plot data colour

  Draw the data contained in the data argument. The data are added to the existing spokes towards the outer circle.

  list data (in)

    List of data (the length should correspond to the number of sectors)

  string colour

    Colour in which the new segments will be drawn

For 3D plots:

$plot3d plotfunc function

  Plot a function defined over two variables x and y. The resolution is determined by the set grid sizes (see the method gridsize for more information).

  string function (in)

    Name of the procedure that calculates the z-value for the given x and y coordinates. The procedure has to accept two float arguments (x is first argument, y is second) and return a floating-point value.

$plot3d plotfuncont function contours

  Plot a function defined over two variables x and y using the contour levels in contours to colour the surface. The resolution is determined by the set grid sizes (see the method gridsize for more information).

  string function (in)

    Name of the procedure that calculates the z-value for the given x and y coordinates. The procedure has to accept two float arguments (x is first argument, y is second) and return a floating-point value.

  list contours (in)

    List of values in ascending order that represent the contour levels (the boundaries between the colours in the contour map).

$plot3d gridsize nxcells nycells

  Set the grid size in the two directions. Together they determine how many polygons will be drawn for a function plot.

  int nxcells (in)

    Number of grid cells in x direction. Has to be an integer number greater than zero.

  int nycells (in)

    Number of grid cells in y direction. Has to be an integer number greater than zero.

$plot3d plotdata data

  Plot a matrix of data.

  list data (in)

    The data to be plotted. The data has to be provided as a nested list with 2 levels. The outer list contains rows, drawn in y-direction, and each row is a list whose elements are drawn in x-direction, for the columns. Example:

            set data {
            {1.0 2.0 3.0}
            {4.0 5.0 6.0}
            }

$plot3d interpolatedata data contours

  Plot the data using bilinear interpolation with the contour levels in contours to colour the surface. The resolution is determined by the set grid sizes (see the method gridsize for more information).

  list data (in)

    The data to be plotted, just as for the plotdata subcommand.

  list contours (in)

    List of values in ascending order that represent the contour levels (the boundaries between the colours in the contour map).

$plot3d colour fill border

  Configure the colour to use for polygon borders and inner area. Note: The "color" subcommand is a synonym.

  color fill (in)

    The colour to use for filling the polygons.

  color border (in)

    The colour to use for the border of the polygons.

$plot3d ribbon yzpairs

  Plot a ribbon based on the pairs of yz-coordinates. The colours for the ribbon itself and the edge are taken from the colours option.

  list yzpairs (in)

    List of pairs of yz-coordinates

For 3D ribbon plots:

$plot3d plot yzpairs

  Plot a ribbon based on the pairs of yz-coordinates. The colours for the ribbon itself and the edge are taken from the colours option.

  list yzpairs (in)

    List of pairs of yz-coordinates

For xy plots, stripcharts, histograms, polar plots and ternary diagrams:

$xyplot dataconfig series -option value ...

  Set the value for one or more options regarding the drawing of data of a specific series.

  string series (in)

    Name of the data series whose configuration we are changing.

  The following options are allowed:

  colour c
  color c

    The colour to be used when drawing the data series.

  type enum

    The drawing mode chosen for the series. This can be one of line, symbol, or both.

  symbol enum

    What kind of symbol to draw. The value of this option is ignored when the drawing mode line was chosen. This can be one of plus, cross, circle, up (triangle pointing up), down (triangle pointing down), dot (filled circle), upfilled or downfilled (filled triangles).

  radius integer

    The size of the radius of the symbol. The total width of the symbol will be 2 times the radius size. The default radius is 4.

  width integer

    The width of the line (if drawn) or the width of the polygon outline (if -filled).

  filled enum

    Whether to fill the area above or below the data line or not. Can be one of: no, up or down (SPECIAL EFFECTS)

  fillcolour colour

    Colour to use when filling the area associated with the data line.

  style enum

    The style to be used for histograms:

    - filled: Fill the area under the data points with bars (default)

    - spike: Draw vertical lines from the y-axis (lower boundary) to the data point

    - symbol: Draw a symbol at the data point

    - plateau: Draw a horizontal line at the height of the data point

    - stair: Draw a continuous stair-like line connecting the data points

  smooth boolean

    (Used with ternary diagrams) Whether to draw the lines and filled polygons with the smooth option on (rounded corners) or not.

For piecharts and spiral pies:

$pie plot data

  Fill a piechart.

  list data (in)

    A list of pairs (labels and values). The values determine the relative size of the circle segments. The labels are drawn beside the circle.

$pie colours colour1 colour2 ...

  Set the colours to be used.

  color colour1 (in)

    The first colour.

  color colour2 (in)

    The second colour, and so on.

$pie explode segment

  Explode a segment (that is: move one segment out of the circle). If the segment is indicated as "auto", then you can click on a segment. This will be exploded instead of any previously exploded segment.

  int segment

    The segment to be exploded or "auto" if you want to do this interactively.

For radial charts:

$radial plot data colour thickness

  Draw a new line in the radial chart

  list data (in)

    A list of data (one for each spoke). The values determine the distance from the centre of the line connecting the spokes.

  color colour (in)

    The colour for the line.

  int thickness (in)

    An optional argument for the thickness of the line.

$pie colours colour1 colour2 ...

  Set the colours to be used.

  color colour1 (in)

    The first colour.

  color colour2 (in)

    The second colour, and so on.

For vertical barcharts:

$barchart plot series ydata colour ?dir? ?brightness?

  Add a data series to a barchart. The bars are tagged with a tag "data_\$series" to identify them.

  string series (in)

    Name of the series the values belong to.

  list ydata (in)

    A list of values, one for each x-axis label.

  color colour (in)

    The colour of the bars.

  string dir (in)

    If given, "top-down" or "bottom-up", to indicate the direction in which the colour changes. (If not given, a uniform colour is used).

  string brightness (in)

    If given, "bright" or "dark" (defaulting to "bright"). The colour will change to respectively white or black, depending on the direction.

$barchart config -option value ...

  Set options for drawing the bars.

  showvalues boolean

    Whether to show the values or not (above the bars)

  valuefont newfont

    Name of the font to use for the values

  valuecolour colour

    Colour for the values

  valueformat format

    Format string to use for formatting the values

For horizontal barcharts:

$barchart plot series xdata colour ?dir? ?brightness?

  Add a data series to a barchart. The bars are tagged with a tag "data_\$series" to identify them.

  string series (in)

    Name of the series the values belong to.

  list xdata (in)

    A list of values, one for each y-axis label.

  color colour (in)

    The colour of the bars.

  string dir (in)

    If given, "left-right" or "right-left", to indicate the direction in which the colour changes. (If not given, a uniform colour is used).

  string brightness (in)

    If given, "bright" or "dark" (defaulting to "bright"). The colour will change to respectively white or black, depending on the direction.

$barchart config -option value ...

  Set options for drawing the bars.

  showvalues boolean

    Whether to show the values or not (to the right of the bars)

  valuefont newfont

    Name of the font to use for the values

  valuecolour colour

    Colour for the values

  valueformat format

    Format string to use for formatting the values

For 3D barcharts:

$barchart plot label yvalue colour

  Add the next bar to the barchart.

  string label (in)

    The label to be shown below the column.

  float yvalue (in)

    The value that determines the height of the column

  color colour (in)

    The colour of the column.

$barchart config -option value ...

  Set one or more configuration parameters. The following options are supported:

  usebackground boolean

    Whether to draw walls to the left and to the back of the columns or not

  useticklines boolean

    Whether to draw ticklines on the walls or not

  showvalues boolean

    Whether to show the values or not

  labelfont newfont

    Name of the font to use for labels

  labelcolour colour

    Colour for the labels

  valuefont newfont

    Name of the font to use for the values

  valuecolour colour

    Colour for the values

For 3D ribbon charts:

$ribbon line xypairs colour

  Plot the given xy-pairs as a ribbon in the chart

  list xypairs (in)

    The pairs of x/y values to be drawn (the series is drawn as a whole)

  color colour (in)

    The colour of the ribbon.

$ribbon area xypairs colour

  Plot the given xy-pairs as a ribbon with a filled area in front. The effect is that of a box with the data as its upper surface.

  list xypairs (in)

    The pairs of x/y values to be drawn (the series is drawn as a whole)

  color colour (in)

    The colour of the ribbon/area.

For boxplots:

$boxplot plot series label values

  Add a box-and-whisker to the plot. The dataconfig command can be used to customize the box-and-whisker (see the box-and-whiskers command for the xyplot for details).

  string series (in)

    Name of the data series the box belongs to

  string label (in)

    The label along the x- or y-axis to which the data belong

  list values (in)

    List of raw values, the extent of the box and the whiskers will be determined from this list.

For timecharts:

$timechart period text time_begin time_end colour

  Add a time period to the chart.

  string text (in)

    The text describing the period.

  string time_begin (in)

    Start time of the period.

  string time_end (in)

    Stop time of the period.

  color colour (in)

    The colour of the bar (defaults to black).

$timechart addperiod time_begin time_end colour

  Add a new period to the current row in the chart. This allows you to highlight several periods in the same row. No new text is drawn.

  string time_begin (in)

    Start time of the period.

  string time_end (in)

    Stop time of the period.

  color colour (in)

    The colour of the bar (defaults to black).

$timechart milestone text time colour

  Add a milestone (represented as an point-down triangle) to the chart.

  string text (in)

    The text describing the milestone.

  string time (in)

    Time at which the milestone must be positioned.

  color colour (in)

    The colour of the triangle (defaults to black).

$timechart addmilestone time colour

  Add another milestone to the current row in the chart.

  string time (in)

    Time at which the milestone must be positioned.

  color colour (in)

    The colour of the triangle (defaults to black).

$timechart vertline text time colour

  Add a vertical line (to indicate the start of the month for instance) to the chart in the specified colour.

  string text (in)

    The text appearing at the top (an abbreviation of the date/time for instance).

  string time (in)

    Time at which the line must be positioned.

  color colour (in)

    The colour of the line to be drawn (defaults to black)

$timechart hscroll scrollbar

  Connect a horizontal scrollbar to the chart. See also the section on scrolling.

  widget scrollbar (in)

    The horizontal scrollbar that is to be connected to the chart

$timechart vscroll scrollbar

  Connect a vertical scrollbar to the chart. See also the section on scrolling.

  widget scrollbar (in)

    The vertical scrollbar that is to be connected to the chart

For Gantt charts:

$ganttchart task text time_begin time_end completed

  Add a task with its period and level of completion to the chart. Returns a list of canvas items that can be used for further manipulations, like connecting two tasks.

  string text (in)

    The text describing the task.

  string time_begin (in)

    Start time of the task.

  string time_end (in)

    Stop time of the task.

  float completed (in)

    The percentage of the task that is completed.

$ganttchart milestone text time colour

  Add a milestone (represented as an point-down triangle) to the chart.

  string text (in)

    The text describing the milestone.

  string time (in)

    Time at which the milestone must be positioned.

  color colour (in)

    The colour of the triangle (defaults to black).

$ganttchart vertline text time

  Add a vertical line (to indicate the start of the month for instance) to the chart.

  string text (in)

    The text appearing at the top (an abbreviation of the date/time for instance).

  string time (in)

    Time at which the line must be positioned.

$ganttchart connect from to

  Add an arrow that connects the from task with the to task.

  list from (in)

    The list of items returned by the "task" command that represents the task from which the arrow starts.

  string text (in)

    The text summarising the tasks

  list args (in)

    One or more tasks (the lists returned by the "task" command). They are shifted down to make room for the summary.

  list to (in)

    The list of items returned by the "task" command that represents the task at which the arrow ends.

$ganttchart summary text args

  Add a summary item that spans all the tasks listed. The graphical representation is a thick bar running from the leftmost task to the rightmost.

  Use this command before connecting the tasks, as the arrow would not be shifted down!

  string text (in)

    The text summarising the tasks

  list args (in)

    One or more tasks (the lists returned by the "task" command). They are shifted down to make room for the summary.

$ganttchart color keyword newcolor

  Set the colour of a part of the Gantt chart. These colours hold for all items of that type.

  string keyword (in)

    The keyword indicates which part of the Gantt chart to change:

    - description - the colour of the descriptive text

    - completed - the colour of the filled bar representing the completed part of a task

    - left - the colour for the part that is not yet completed

    - odd - the background colour for the odd entries

    - even - the background colour for the even entries

    - summary - the colour for the summary text

    - summarybar - the colour for the bar for a summary

  string newcolor (in)

    The new colour for the chosen items.

$ganttchart font keyword newfont

  Set the font of a part of the Gantt chart. These fonts hold for all items of that type.

  string keyword (in)

    The keyword indicates which part of the Gantt chart to change:

    - description - the font used for descriptive text

    - summary - the font used for summaries

    - scale - the font used for the time scale

  string newfont (in)

    The new font for the chosen items.

$ganttchart hscroll scrollbar

  Connect a horizontal scrollbar to the chart. See also the section on scrolling.

  widget scrollbar (in)

    The horizontal scrollbar that is to be connected to the chart

$ganttchart vscroll scrollbar

  Connect a vertical scrollbar to the chart. See also the section on scrolling.

  widget scrollbar (in)

    The vertical scrollbar that is to be connected to the chart

For isometric plots (to be extended):

$isoplot plot rectangle x1 y1 x2 y2 colour

  Plot the outlines of a rectangle.

  float x1 (in)

    Minimum x coordinate of the rectangle to be drawn.

  float y1 (in)

    Minimum y coordinate of the rectangle.

  float x2 (in)

    Maximum x coordinate of the rectangle to be drawn.

  float y2 (in)

    Maximum y coordinate of the rectangle.

  color colour (in)

    The colour of the rectangle.

$isoplot plot filled-rectangle x1 y1 x2 y2 colour

  Plot a rectangle filled with the given colour.

  float x1 (in)

    Minimum x coordinate of the rectangle to be drawn.

  float y1 (in)

    Minimum y coordinate of the rectangle.

  float x2 (in)

    Maximum x coordinate of the rectangle to be drawn.

  float y2 (in)

    Maximum y coordinate of the rectangle.

  color colour (in)

    The colour of the rectangle.

$isoplot plot circle xc yc radius colour

  Plot the outline of a circle.

  float xc (in)

    X coordinate of the circle's centre.

  float yc (in)

    Y coordinate of the circle's centre.

  color colour (in)

    The colour of the circle.

$isoplot plot filled-circle xc yc radius colour

  Plot a circle filled with the given colour.

  float xc (in)

    X coordinate of the circle's centre.

  float yc (in)

    Y coordinate of the circle's centre.

  color colour (in)

    The colour of the circle.

For tables you can use the following subcommands:

$table row items

  Draw a single row of items. The appearance of the items can be controlled explicitly via the format command.

  list items (in)

    List of text items to be drawn, one per column

$table separator

  Draw a horizontal line to separate two rows

$table formatcommand procname

  Set the procedure that controls the formatting of items. By default items are simply drawn as centered text.

  string procname (in)

    Name of the procedure to be used. Its signature is:

        proc procname {table widget row column value} {...}

    Use the cellconfigure subcommand to set the attributes per cell.

$table cellconfigure args

  Set the attributes for the next cell(s) to be drawn.

  list args (in)

    Key-value pairs: -background sets the background colour of the cells, -cell sets the foreground colour, -font sets the text font, -anchor sets the position of the text within the cell and -justify controls the layout of multiline text.

For ternary diagrams you can use the following subcommands:

$ternary plot series xcrd ycrd zcrd text dir

  Draw a single data point with a label. The three coordinates are scaled so that a unique point in the triangle results. A label is drawn next to it.

  string series (in)

    Name of the data series the point belongs to (used to determine colour and symbol)

  float xcrd (in)

    X-coordinate of the data point (refers to the lower-left corner).

  float ycrd (in)

    Y-coordinate of the data point (refers to the lower-right corner).

  float zcrd (in)

    Z-coordinate of the data point (refers to the top corner).

  string text (in)

    Label describing the data point.

  string dir (in)

    Optional string indicating the direction in which to plot the label (e, n, etc.)

$ternary line series coords

  Draw a continuous line based on the given coordinates (triplets).

  string series (in)

    Name of the data series the line belongs to (used to determine colour and smoothness)

  list coords (in)

    The coordinates of the points that determine the line (note that a point is defined by three coordinates).

$ternary fill series coords

  Draw a filled polygon based on the given coordinates (triplets).

  string series (in)

    Name of the data series the polygon belongs to (used to determine colour and smoothness)

  list coords (in)

    The coordinates of the points that determine the polygon (note that a point is defined by three coordinates).

$ternary text xtext ytext ztext

  Draw text at the three corners of the diagram to identify the components.

  string xtext (in)

    Text to be plotted at the lower-left corner

  string ytext (in)

    Text to be plotted at the lower-right corner

  string ztext (in)

    Text to be plotted at the top corner

$ternary ticklines colour

  Draw ticklines to facilitate reading off the diagram.

  string colour (in)

    Optional argument used as the colour of the ticklines. Defaults to grey.

For status timeline plots you can use the following subcommands:

$timeline plot series item start stop color

  Draw a bar in the given colour from start to stop for the item item. The item is a convenient label - there is no relation to the labels along the axis. The items are drawn from bottom to top.

  string item (in)

    Name to identify the bar. See remark above.

  float start (in)

    X-coordinate (or time) at which the bar starts

  float stop (in)

    X-coordinate (or time) at which the bar stops

  string color (in)

    Colour to use for the bar. Defaults to black.

$timeline vertline text time args

  Draw a vertical line to indicate a significant moment.

  string text (in)

    Text to identify the moment.

  float time (in)

    X-coordinate (or time) at which the line is to be drawn

  list args (in)

    Individual optional arguments that will be passed to the create line subcommand of the underlying canvas. This way you can set the colour or the line width of the vertical line.

## COORDINATE TRANSFORMATIONS

Besides the commands that deal with the plots and charts directly, there are a number of commands that can be used to convert world coordinates to pixels and vice versa. These include:

::Plotchart::viewPort w pxmin pymin pxmax pymax

  Set the viewport for window w. Should be used in cooperation with ::Plotchart::worldCoordinates.

  widget w (in)

    Name of the window (canvas widget) in question.

  float pxmin (in)

    Left-most pixel coordinate.

  float pymin (in)

    Top-most pixel coordinate (remember: the vertical pixel coordinate starts with 0 at the top!).

  float pxmax (in)

    Right-most pixel coordinate.

  float pymax (in)

    Bottom-most pixel coordinate.

::Plotchart::worldCoordinates w xmin ymin xmax ymax

  Set the extreme world coordinates for window w. The world coordinates need not be in ascending order (i.e. xmin can be larger than xmax, so that a reversal of the x-axis is achieved).

  widget w (in)

    Name of the window (canvas widget) in question.

  float xmin (in)

    X-coordinate to be mapped to left side of viewport.

  float ymin (in)

    Y-coordinate to be mapped to bottom of viewport.

  float xmax (in)

    X-coordinate to be mapped to right side of viewport.

  float ymax (in)

    Y-coordinate to be mapped to top side of viewport.

::Plotchart::world3DCoordinates w xmin ymin zmin xmax ymax zmax

  Set the extreme three-dimensional world coordinates for window w. The world coordinates need not be in ascending order (i.e. xmin can be larger than xmax, so that a reversal of the x-axis is achieved).

  widget w (in)

    Name of the window (canvas widget) in question.

  float xmin (in)

    X-coordinate to be mapped to front side of the 3D viewport.

  float ymin (in)

    Y-coordinate to be mapped to left side of the viewport.

  float zmin (in)

    Z-coordinate to be mapped to bottom of viewport.

  float xmax (in)

    X-coordinate to be mapped to back side of viewport.

  float ymax (in)

    Y-coordinate to be mapped to right side of viewport.

  float zmax (in)

    Z-coordinate to be mapped to top side of viewport.

::Plotchart::coordsToPixel w x y

  Return a list of pixel coordinates valid for the given window.

  widget w (in)

    Name of the canvas alias (as returned by [\$anyplot canvas]) in question.

  float x (in)

    X-coordinate to be mapped.

  float y (in)

    Y-coordinate to be mapped.

::Plotchart::coords3DToPixel w x y z

  Return a list of pixel coordinates valid for the given window.

  widget w (in)

    Name of the canvas alias (as returned by [\$anyplot canvas]) in question.

  float x (in)

    X-coordinate to be mapped.

  float y (in)

    Y-coordinate to be mapped.

  float y (in)

    Z-coordinate to be mapped.

::Plotchart::polarCoordinates w radmax

  Set the extreme polar coordinates for window w. The angle always runs from 0 to 360 degrees and the radius starts at 0. Hence you only need to give the maximum radius. Note: If the viewport is not square, this procedure will not adjust the extremes, so that would result in an elliptical plot. The creation routine for a polar plot always determines a square viewport.

  widget w (in)

    Name of the canvas alias (as returned by [\$anyplot canvas]) in question.

  float radmax (in)

    Maximum radius.

::Plotchart::polarToPixel w rad phi

  Wrapper for a call to ::Plotchart::coordsToPixel. Note: This procedure has been deprecated - you should use the procedure ::Plotchart::coordsToPixel instead.

  widget w (in)

    Name of the canvas alias (as returned by [\$anyplot canvas]) in question.

  float rad (in)

    Radius of the point.

  float phi (in)

    Angle to the positive x-axis.

::Plotchart::pixelToCoords w x y

  Return a list of world coordinates valid for the given window.

  widget w (in)

    Name of the canvas alias (as returned by [\$anyplot canvas]) in question.

  float x (in)

    X-pixel to be mapped.

  float y (in)

    Y-pixel to be mapped.

::Plotchart::pixelToIndex w x y

  Return the index of the pie segment containing the pixel coordinates (x,y)

  widget w (in)

    Name of the canvas alias (as returned by [\$anyplot canvas]) in question, holding a piechart.

  float x (in)

    X-pixel to be mapped.

  float y (in)

    Y-pixel to be mapped.

Furthermore there is a routine to determine "pretty" numbers for use with an axis:

::Plotchart::determineScale xmin xmax inverted

  Determine "pretty" numbers from the given range and return a list containing the minimum, maximum and stepsize that can be used for a (linear) axis.

  float xmin (in)

    Rough minimum value for the scaling

  float xmax (in)

    Rough maximum value for the scaling.

  boolean inverted (in)

    Optional argument: if 1, then the returned list produces an inverted axis. Defaults to 0 (the axis will be from minimum to maximum)

::Plotchart::determineScaleFromList values inverted

  Determine "pretty" numbers from the given list of values and return a list containing the minimum, maximum and stepsize that can be used for a (linear) axis.

  float values (in)

    List of values that will be examined. May contain missing values (empty strings)

  boolean inverted (in)

    Optional argument: if 1, then the returned list produces an inverted axis. Defaults to 0 (the axis will be from minimum to maximum)

## MISSING VALUES

Often data that need to be plotted contain gaps - in a series of measurement data, they can occur because the equipment failed, a sample was not collected correctly or for many other reasons. The Plotchart handles these gaps by assuming that one or both coordinates of such data points are an empty string:

        #
        # Create the plot with its x- and y-axes
        #
        set s [::Plotchart::createXYPlot .c {0.0 100.0 10.0} {0.0 100.0 20.0}]
        foreach {x y} {0.0 32.0 10.0 {} 25.0 60.0 78.0 11.0 } {
            $s plot series1 $x $y
        }

The effect varies according to the type of plot:

- For xy-plots, radial plots and strip charts the missing data point causes a gap in the line through the points.

- For barchats, missing values are treated as if a value of zero was given.

- For time charts and Gantt charts missing values cause errors - there is no use for them there.

## OTHER OUTPUT FORMATS

Besides output to the canvas on screen, the module is capable, via canvas postscript, of producing PostScript files. One may wonder whether it is possible to extend this set of output formats and the answer is "yes". This section tries to sum up the aspects of using this module for another sort of output.

One way you can create output files in a different format, is by examining the contents of the canvas after everything has been drawn and render that contents in the right form. This is probably the easiest way, as it involves nothing more than the re-creation of all the elements in the plot that are already there.

The drawback of that method is that you need to have a display, which is not always the case if you run a CGI server or something like that.

An alternative is to emulate the canvas command. For this to work, you need to know which canvas subcommands are used and what for. Obviously, the create subcommand is used to create the lines, texts and other items. But also the raise and lower subcommands are used, because with these the module can influence the drawing order - important to simulate a clipping rectangle around the axes. (The routine DrawMask is responsible for this - if the output format supports proper clipping areas, then a redefinition of this routine might just solve this).

Furthermore, the module uses the cget subcommand to find out the sizes of the canvas. A more mundane aspect of this is that the module currently assumes that the text is 14 pixels high and that 80 pixels in width suffice for the axis' labels. No "hook" is provided to customise this.

In summary:

- Emulate the create subcommand to create all the items in the correct format

- Emulate the cget subcommand for the options -width and -height to allow the correct calculation of the rectangle's position and size

- Solve the problem of raising and lowering the items so that they are properly clipped, for instance by redefining the routine DrawMask.

- Take care of the currently fixed text size properties

## SPECIAL EFFECTS

As an example of some special effects you can achieve, here is the code for a plot where the area below the data line varies in colour:

    canvas .c  -background white -width 400 -height 200
    pack .c -fill both
    set s [::Plotchart::createXYPlot .c {0.0 100.0 10.0} {0.0 100.0 20.0}]
    $s background gradient green top-down
    $s dataconfig series1 -filled up -fillcolour white
    $s plot series1  0.0 20.0
    $s plot series1 10.0 20.0
    $s plot series1 30.0 50.0
    $s plot series1 35.0 45.0
    $s plot series1 45.0 25.0
    $s plot series1 75.0 55.0
    $s plot series1 100.0 55.0
    $s plaintext 30.0 60.0 "Peak" south

The trick is to fill the background with a colour that changes from green at the top to white at the bottom. Then the area above the data line is filled with a white polygon. Thus the green shading varies with the height of the line.

## ROOM FOR IMPROVEMENT

In this version there are a lot of things that still need to be implemented:

- More robust handling of incorrect calls (right now the procedures may fail when called incorrectly):

  - The axis drawing routines can not handle inverse axes right now.

  - If the user provides an invalid date/time string, the routines simply throw an error.

## RESIZING

Plotchart has not been designed to create plots and charts that keep track of the data that are put in. This means that if an application needs to allow the user to resize the window holding the plot or chart, it must take care to redraw the complete plot.

The code below is a simple example of how to do that:

    package require Plotchart
    grid [canvas .c -background white] -sticky news
    grid columnconfigure . 0 -weight 1
    grid rowconfigure . 0 -weight 1
    bind .c <Configure> {doResize}
    proc doPlot {} {
        #
        # Clean up the contents (see also the note below!)
        #
        .c delete all
        #
        # (Re)draw the bar chart
        #
        set p [::Plotchart::createBarchart .c {x y z} {0 100 10} 3]
        $p plot R {10 30 40} red
        $p plot G {30 40 60} green
    }
    proc doResize {} {
        global redo
        #
        # To avoid redrawing the plot many times during resizing,
        # cancel the callback, until the last one is left.
        #
        if { [info exists redo] } {
            after cancel $redo
        }
        set redo [after 50 doPlot]
    }

Please note: The code above will work fine for barcharts and many other types of plots, but as Plotchart keeps some private information for xy plots, more is needed in these cases. This actually requires a command "destroyPlot" to take care of such details. A next version of Plotchart may have that.

Alternatively, you can use the xyplot package which is built on top of Plotchart. This package supports zooming in and zooming out, as well as resizing the plot as a whole. Here is a small demonstration program:

    # xyplot_demo.tcl --
    #     Demonstration of the xyplot package
    #
    package require xyplot
    set xydata1 {}
    set xydata2 {}
    set xydata3 {}
    set xydata4 {}
    for { set i 0 } { $i < 1024 } { incr i } {
        lappend xydata1 [expr {$i-1000}] [expr {$i * sin($i/4096.0*3.1415*2) * (sin($i/256.0*3.1415*2))}]
        lappend xydata2 [expr {$i-1000}] [expr {$i * sin($i/4096.0*3.1415*2) * (sin($i/256.0*3.1415*2) + 0.25 * sin($i/256.0*3.1415*6))}]
        lappend xydata3 [expr {$i-1000}] [expr {$i * sin($i/4096.0*3.1415*2) * (sin($i/256.0*3.1415*2) + 0.25 * sin($i/256.0*3.1415*6) + 0.0625 * sin($i/256.0*3.1415*10))}]
        lappend xydata4 [expr {$i-1000}] [expr {$i * sin($i/4096.0*3.1415*2) * (sin($i/256.0*3.1415*2) + 0.25 * sin($i/256.0*3.1415*6) + 0.0625 * sin($i/256.0*3.1415*10) + 0.015625 * sin($i/256.0*3.1415*14))}]
    }
    set xyp [xyplot .xyp -xformat "%5.0f" -yformat "%5.0f" -title "XY plot testing" -background gray90]
    pack $xyp -fill both -expand true
    set s1 [$xyp add_data sf1 $xydata1 -legend "Serie 1 data" -color red]
    set s2 [$xyp add_data sf2 $xydata2 -legend "Serie 2 data" -color green]
    set s3 [$xyp add_data sf3 $xydata3 -legend "Serie 3 data" -color blue]
    set s4 [$xyp add_data sf4 $xydata4 -legend "Serie 4 data" -color orange]
    set xyp2 [xyplot .xyp2 -xticks 8 -yticks 4 -yformat %.2f -xformat %.0f]
    pack $xyp2 -fill both -expand true
    set s1 [$xyp2 add_data sf1 $xydata1]
    set s2 [$xyp2 add_data sf2 $xydata2]
    set s3 [$xyp2 add_data sf3 $xydata3]
    set s4 [$xyp2 add_data sf4 $xydata4]

Zooming in is done by selecting a rectangle with the left mouse button pressed. Zooming out is done by pressing the right mouse button. If you resize the window, the canvases inside are resized too. If you zoom in, you can scroll the plot via the scrollbars that are automatically attached.

## ZOOMING IN

As the Plotchart package does not keep track of the data itself, rescaling an existing plot - for instance when zooming in - would have to be done by redefining the plot and redrawing the data. However, the canvas widget offers a way out by scaling and moving items, so that zooming in becomes a bit simpler.

Whether zooming is indeed useful, depends on the type of plot. Currently it is defined for XY-plots only. The method is called "rescale" and simply redraws the axes and scales and moves the data items so that they conform to the new axes. The drawback is that any symbols are scaled by the same amount. The rescale method works best for plots that only have lines, not symbols.

The method works very simply:

       $p rescale {newxmin newxmax newxstep} {newymin newymax newystep}

## CONFIGURATION OPTIONS AND OTHER COMMANDS

The commands plotconfig and plotstyle can be used to set all manner of options. The command eraseplot can be used to completely erase a plot or chart. The syntax of these commands is:

::Plotchart::plotconfig charttype component property value

  Set a new value for the property of a component in a particular chart or plot type or query its current value. Changed properties only have effect for the consecutive plots, not for the ones already created. Each argument is optional.

  Note: The plotstyle command offers a more flexible way to control the configuration options.

  string charttype (in)

    The type of chart or plot (see the configuration type that is mentioned for each create command). If not given or empty, a list of chart types is returned. If it is given, the properties for that particular type are used.

  string component (in)

    The component of the plot/chart: leftaxis, rightaxis, background, margin and so on. If not given or empty, a list of components is returned. If it is given, the properties for that particular component will be set for that particular type of chart.

  string property (in)

    The property of the component of the plot/chart: textcolor, thickness of the axis line, etc. If not given or empty, a list of properties is returned. If it is given, that particular property for that particular component will be set for that particular type of chart.

  string value (in)

    The new value for the property. If empty, the current value is returned. If the value is "default", the default value will be restored.

    Note, that in some cases an empty value is useful. Use "none" in this case - it can be useful for colours and for formats.

::Plotchart::plotstyle subcmd style args

  Manipulate the style in which subsequent plots will be drawn. The default style is "default", but you can define and load any number of other styles.

  string subcmd (in)

    The subcommand to be executed:

    - configure - this subcommand allows you to set the options per chart type. It takes the same options as the plotconfig command.

    - current - return the current style

    - load - make the given style the active style for subsequent plots and charts

    - names - return the list of currently defined styles

  string style (in)

    The name of the plot style to manipulate

  list args (in)

    The new options for the style. Each option is described by: chart type, component of the chart, property of the component and the new value for the property - see the plotconfig command for details.

Below is a detailed list of the components and properties:

- Axes come in a wide variety:

  - leftaxis, rightaxis, topaxis, bottomaxis for the plots with a rectangular shape.

  - xaxis, yaxis and zaxis are used for the 3D plots

  - axis, this represents the radial and tangential axes of a polar plot

  All axes have the following properties:

  - color - the colour of the line and the tickmarks

  - thickness - the width of the line of the axis itself, not the tickmarks

  - ticklength - the length of the tickmarks in pixels. A positive value is outward, a negative value is inward.

  - font - the font for the labels and the text at the axis

  - format - the format for rendering the (numerical) labels. For the time axis it is the format for a date and time.

  - textcolor - the colour for the labels and the text.

  - labeloffset - space (in pixels) between the tickmark and the actual label

  - minorticks - number of minor tickmarks between the major tickmarks

  - shownumbers - show the numbers/labels or not.

  - showaxle - show the axis line or not.

- The margin is important for the layout. Currently only the rectangular plots allow the margins to be set: left, right, top and bottom. The values are in pixels.

- The text component is meant for any text appearing via the plaintext subcommand. The properties are: textcolor, font and anchor (positioning of the text relative to the given coordinates).

- The background has two properties: outercolor, the colour outside of the actual plot, and innercolor, the colour inside the plot. (Note: only "outercolor" has now been implemented).

- The mask has one property only: draw. If set to 1, the default, white rectangles are drawn to mimick the effects of clipping - excess data are made invisible this way. Otherwise these rectangles are not drawn. This is useful to control the layout more tightly, for instance with multiple plots in one canvas.

- The title component has the same properties as the text component (but it is independent of that component). It also has a background property: If not set (or set to the empty string) this is the same as the outercolor property of the background component, otherwise it is a separate colour.

- The legend has three properties: background, border and position. See the legend subcommand for the meaning.

- The bar components is used for all barchart-like plots and has three properties: barwidth (relative width of the bars in relation to the items along the axis), innermargin (the relative width of the gaps between bars or groups of bars) and the outline colour.

- The labels component is used to describe the appearance of the labels of piecharts and "spiral" piecharts. The properties are:

  - textcolor - colour of the label text

  - font - font to be used for the label text

  - placement - out of the circle or in the circle

  - sorted - the data are sorted in ascending order first

  - shownumbers - the labels are combined with the numbers according to the format

  - format - the format to be used (defaults to: "%s (%g)") if the numbers are to shown. The format command gets the label first, then the number)

  - formatright - if given, the format to be used for labels and numbers appearing to the right of the pie. The format command gets the number first, then the label. (Defaults to "")

- The slice component has properties to control the appearance of the sections in the pie diagram:

  - outline - the colour of the line around the slices (default: black)

  - outlinewidth - width of the line around the slices (default: 1 pixel)

  - startangle - the angle w.r.t. positive x-axis where the first slice starts

  - direction - the direction in which to draw the slices (default: +, that is clockwise)

- The table charts use the general components title and margin and further more the specific components header, oddrow, evenrow, cell and frame:

  - header, oddrow and evenrow have the properties: background, font, color, height and anchor with obvious meanings.

  - The cell component defines in addition leftspace, rightspace and topspace for fine-grained control of the spacing inside the cell. These are not set via the cellconfigure subcommand however.

  - Finally the frame component uses color, outerwidth (for the width of the line surrounding the whole table) and innerwidth (for the width of lines separating columns and rows).

  ::Plotchart::eraseplot anyplot

    Erase the plot/chart with all resources connected to it.

    string anyplot (in)

      The plot/chart command. All canvas items associated with this command and all internal resources will be removed, including the plot/chart command itself.

See the examples in plotdemos7.tcl for its use.

## SCROLLING FOR TIMECHARTS AND GANTT CHARTS

For two types of plots automatic scrolling management has been implemented: timecharts and Gantt charts. The subcommands hscroll and vscroll associate (existing) scrollbars to the plot, in much the same way as for text and canvas widgets.

Once the association is made, the scrollbars are automatically updated if:

- You add an item with a period wider than the current one.

- You add a vertical line for a time beyond the current bounds.

- You add an extra item beyond the number that was used to create the chart.

For instance:

    package require Plotchart
    canvas .c -width 400 -height 200
    scrollbar .y -orient vertical
    scrollbar .x -orient horizontal
    grid .c .y -sticky news
    grid .x    -sticky news
    source plotchart.tcl
    set s [::Plotchart::createTimechart .c "1 january 2004"  "31 december 2004" 4]
    $s period "Spring" "1 march 2004" "1 june 2004" green
    $s period "Summer" "1 june 2004" "1 september 2004" yellow
    $s vertline "1 jan" "1 january 2004"
    $s vertline "1 apr" "1 april 2004"
    $s vertline "1 jul" "1 july 2004"
    $s vertline "1 oct" "1 october 2004"
    $s vertline "1 jan" "1 january 2005"
    $s vertline "1 apr" "1 april 2005"
    $s vertline "1 jul" "1 july 2005"
    $s milestone "Longest day" "21 july 2004"
    $s milestone "Longest day 2" "21 july 2004"
    $s milestone "Longest day 3" "21 july 2004"
    $s milestone "Longest day 4" "21 july 2004"
    $s milestone "Longest day 5" "21 july 2004"
    $s milestone "Longest day 6" "21 july 2004"
    $s title "Seasons (northern hemisphere)"
    $s vscroll .y
    $s hscroll .x

The original extent of the chart is from 1 january 2004 to 31 december 2004. But because of the addition of vertical lines in 2005 and more items than was specified at the creation of the chart, both the horizontal and the vertical scrollbar will be enabled.

## SPECIALISED PLOTS

Most of the plot and chart types described above have a fairly general use and you simply prepares the data to be plotted yourself. This section describes several plot types that are more specialised, in the sense that they have specific purposes and you pass raw data that are then processed in the plotting routines.

Currently there are the following types:

- Target diagrams are used to assess the capacity of numerical models to reproduce measurement data. They are described in detail in:

      Jason K. Joliff et al.
          Summary diagrams for coupled hydrodynamic-ecosystem model skill assessment
          Journal of Marine Systems 76 (2009) 64-82
          DOI: 10.1016/j.jmarsys.2008.05.014

- Performance profiles are used for comparing the performance of numerical methods or implementations thereof with each other. For more information:

      Desmond Higham and Nicholas Higham
          Matlab Guide
          SIAM, 2005, Philadephia

Most of the general methods for XY-plots work for these plots as well, but their creation and the methods to plot the data are very specific.

::Plotchart::createTargetDiagram w limits scale

  Create a new target diagram with circles indicating specific limits. The x-axis represents the unbiased "root-mean-square difference" (typically varying between -1 and 1) and the y-axis represents the normalised bias.

  Data points closer to the origin represent better results than data points further away.

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  list limits (in)

    List of radii for the circles that represent the limits (for instance: 0.5 and 0.7)

  double scale (in)

    Scale for the axes - defaults to 1, but if the model results are a poor fit, then that may be too small a value. Both axes are scaled in the same way.

$target plot series xvalues yvalues

  The plot method takes two series of data of the same length, the first one representing the model results, the second one represent the measurements or, more general, the data that need to be reproduced.

  string series (in)

    Name of the series (it will be plotted as a symbol that is configured via the $target dataconfig command (see the XY-plot equivalent for an explanation)

  list xvalues (in)

    List of model results (missing values are represented as empty strings)

  list yvalues (in)

    List of measured values (missing values are represented as empty strings; only if both the x and the y values are given, is the pair used in the computations)

::Plotchart::createPerformanceProfile w max

  Create a diagram to show the performance of various numerical methods (or solvers). The idea is to first run these methods on a set of problems and measure their performance. The smaller the number the better. Then these methods are compared via a so-called performance profile: the data are scaled and ordered, such that the best method ends up highest.

  Because of the nature of the plot all data must be given at once.

  widget w (in)

    Name of the existing canvas widget to hold the plot.

  float max (in)

    Maximum value for the x-axis (the x-axis is the scaled performance of the series).

$performance plot series_and_data_pairs

  Plot the data for each given method. The data are identified by the series name and the appearance is controlled via prior dataconfig subcommand.

  list series_and_data_pairs (in)

    List of series names and data. All data must be given at once.

The command plotmethod can be used to add new methods for a particular plot or chart type. It is intended to help you develop specialised graphical displays.

::Plotchart::plotmethod charttype methodname plotproc

  Adds a new method for the given plot or chart type. The method is implemented by the command or procedure given in the plotproc argument. The procedure will be called with two extra arguments, the name of the created plot and the canvas widget that contains (see the example below).

  string charttype (in)

    The type of plot or chart that the new method should be added to.

  string methodname (in)

    Name of the method to be used.

  string plotproc (in)

    Name of the command or procedure that implements the method.

Here is a trivial example of how to use this:

    #
    # The custom method "doodle" always adds the text "DOODLE"
    # to the plot
    #
    proc doodle {p w x y} {
        $p plaintext $x $y "DOODLE"
    }
    ::Plotchart::plotmethod xyplot doodle doodle
    #
    # Use it
    pack [canvas .c]
    set p [::Plotchart::createXYPlot .c {0 100 10} {0 20 5}]
    $p doodle 40 10

## TABLE CHARTS

To show what you can do with table charts, here is a simple example that plots a number of random data. The colours depend on the range that the data belong to. For this the procedure setColor is used.

    package require Plotchart
    pack [canvas .c -bg white -height 300] -fill both -expand yes
    ::Plotchart::plotconfig table frame outerwidth 3
    ::Plotchart::plotconfig table frame color red
    set t [::Plotchart::createTableChart .c {"Column 1" "Column 2" "Column 3"} 80]
    proc setColor {table widget row col value} {
        $table cellconfigure -background white -color black
        if { $value < 2.0 } {
            $table cellconfigure -background red -color white
        }
        if { $value > 6.0 } {
            $table cellconfigure -background green
        }
        return [format "%6.3f" $value]
    }
    # Command must already exist ...
    $t formatcommand setColor
    $t title "Demonstration of table charts"
    $t separator
    for {set i 0} {$i < 9} {incr i} {
        set row {}
        for {set j 0} {$j < 3} {incr j} {
            lappend row [expr {10.0 * rand()}]
        }
        if { $i == 3 } {
            $t separator
        }
        $t row $row
    }

## CONTROL DISPLAYS

TODO

## USING DATE/TIME LABELS

The options -timeformat and -gmt are used to control the display of date/time labels along the x-axis for those plot types for which it makes sense. These options were implemented to take care of date/time labels for stripcharts, as you can also use custom labels (the option -xlabels) if the axis is "static". Since this is not the case for stripcharts, this was not an option (Tcllib/Tklib bug 3613718). The example below illustrates how to use the -timeformat option. The -gmt option merely suppresses the handling of daylight saving time by the [clock format] command.

    package require Plotchart
    pack [canvas .c -width 500 -bg white]
    #
    # Note that we need to present the x values as clock seconds
    #
    set start [clock scan  "0:00"]
    set stop  [clock scan "10:00"]
    set s [Plotchart::createStripchart .c [list $start $stop 7200] {0 10 1} -timeformat "%H:%M"]
    foreach {x y} {0 0 2 5 5 2 9 9 12 10} {
        set x [expr {$start + 3600 * $x}] ;# Convert hour to clock seconds
        $s plot a $x $y
    }

The plot subcommand simply interprets the x and y data as straightforward numbers, so that you need to do the conversion from date/time to "clock seconds" yourself.

## ARRANGING MULTIPLE PLOTS IN A CANVAS

The command plotpack allows you to copy the contents of a plot into another canvas widget. This canvas widget does not act as a composite plot, but it can be saved as a PostScript file for instance: Note: the command simply takes a snapshot of the plots/charts as they are at that moment.

::Plotchart::plotpack w dir args

  Copy the contents of the plots/charts into another widget, in a manner similar to the pack geometry manager.

  widget w (in)

    The name of the canvas widget to copy the plots/charts into

  string dir (in)

    The direction of the arrangement - top, left, bottom or right

  list args (in)

    List of plots/charts to be copied.

For example:

        set p1 [createXYPlot ...]
        set p2 [createBarchart ...]
        ... fill the plots ...
        toplevel .t
        pack [canvas .t.c2 -width ...]
        #
        # Copy the two plots above each other in the new canvas
        #
        plotpack .t.c2 top $p1 $p2

A different method is to use the -box and -axesbox options when creating the plot. These control the area in the canvas where the plot or chart will be drawn.

The -box option takes as its value a list of four numbers:

- X-coordinate of the upper-left corner of the area that will contain the plot or chart (simply a canvas coordinate)

- Y-coordinate of the upper-left corner

- Width of the area

- Height of the area

Specifying the width and height makes it easier to reposition the area with respect to other plots.

The -axesbox option is meant to make aligning the axes of a plot with those of other plots easier. The option takes a list of six arguments:

- Identification of the plot with respect to which it should be positioned (the command returned by the creation command).

- The anchor position that should be used (n, nw, ...)

- X-coordinate of the upper-left corner of the area that will contain the plot or chart. This coordinates is taken relative to the anchor position

- Y-coordinate of the upper-left corner

- Width of the axis area

- Height of the axis area

With this option the area the axes occupy is first determined and the complete area is derived from the margins.

For example:

        set p2 [::Plotchart::createXYPlot .c {0 10 1} {-5 5 2.5} -axesbox [list $p1 ne 0 0 200 200]]

will create a second plot whose left axis coincides with the right axis of plot "\$p1" and the top of the axis is at the same heigt as well - because the axes are positioned at a point 0 pixels to the left and 0 pixels below the north-east corner.

## INTERACTIVE USE

Plotchart has several features for interactive use (cf. NOTES ON TAGS):

- The legend can be moved around by pressing mouse button 1 in the legend's box and keeping it down.

- You can use the bindplot and bindlast commands to define actions that are to be taken when the user clicks on an element of the plot or chart. (see below, see also the sample code in plotdemos12.tcl)

- Piecharts can show an "exploded" segment that you can select with mouse button 1.

If you require different forms of interaction, not covered by Plotchart itself, you can use the tags on the various canvas elements to define other bindings.

The bindplot and bindlast are defined as follows:

$anyplot bindplot event command args

  Register a command that will be run whenever the given event occurs in the plot.

  string event

    The event that you want to bind the command to

  string command

    Name of the command/procedure that you want to run. The following arguments are prefixed: the x- and y-coordinates of the point in the plot (the world coordinates!), so that the procedure has the signature:

            cmd $xworld $yworld $string1 $string2 $string3

    assuming the argument "command" is: {cmd A B C}

$anyplot bindlast series event command

  Register a command that will be run when the event occurs within the neighbourhood of the last point added to the given series. (You can use directly after inserting a data point. All such commands will remain active).

  string event

    The event that you want to bind the command to

  list command

    Name of the command/procedure that you want to run. The following arguments are prefixed: the x- and y-coordinates of the point in the plot (the world coordinates!), so that the procedure has the signature:

            cmd $xworld $yworld $string1 $string2 $string3

    assuming the argument "command" is: {cmd A B C}

Here is an example - show the values of the data points in an annotation (from the sample code in plotdemos12.tcl):

    #
    # Procedure for showing an annotation
    #
    proc showAnnotation {xcoord ycoord plot w} {
        $plot balloon $xcoord $ycoord "Data point: [format "%.3f, %.3f" $xcoord $ycoord]" north
        after 2000 [list removeAnnotation $w]
    }
    #
    # Procedure for erase an annotation
    #
    proc removeAnnotation {w} {
        # Use the tags to remove all annotations
        $w delete BalloonText
        $w delete BalloonFrame
    }
    #
    # Create a simple plot and a label
    #
    pack [canvas .c -bg white] [label .l -textvariable coords]
    set p [::Plotchart::createXYPlot .c {0 1000 200} {0 10 1}]
    $p dataconfig series1 -type both -symbol cross
    foreach x {1 2 5 10 20 50 100 200 500 1000} {
        $p plot series1 $x [expr {log($x)}]
        #
        # Show the annotation for each data point
        #
        $p bindlast series1 <Enter> [list showAnnotation $p %W]
    }

## NOTES ON TAGS

The implementation of Plotchart relies heavily on the canvas's ability to identify graphical objects by tags and to change the drawing order of the objects. This section documents the tags that are used.

(Note: the tags are not always used consistently - see the notes appearing with the various tags. This section describes the current state.)

General graphical objects:

- mask - Used to manipulate the opaque rectangles that ensure data outside the viewport are not shown.

- topmask, horizmask, vertmask - specialised tags, used for scrollable plots.

- title - Used for title strings.

- BalloonText, BalloonFrame - Used to manipulate balloon text.

- PlainText - Used to manipulate ordinary text without any decoration.

- background - Tag used for gradient and image backgrounds (and for gradient-filled bars).

- xaxis, yaxis - Tags used for all objects related to horizontal or vertical axes. (also: both for numerical axes and axes with labels as in barcharts). Note, however, that the text along the axes has no particular tag.

- raxis - Tag used for all objects related to a right axis.

- taxis - Tag used for all objects related to a time axis.

- axis3d - Tag used for 3D axes

- xtickline, ytickline - Tags used for ticklines.

- legend, legengb, legendobj - Tags used for the legend. The latter is used to manipulate the legend as a whole.

- legend_series - Tag used to control the appearance of the legend entry ("series" should be replaced by the series name).

- object - used as standard tag for all objects drawn with the ::Plotchart::drawobject procedure. Tags given at object creation time are added to this tag.

XY-plots (all types of axes):

- data - The general tag to identify graphical objects associated with data. data_seriesname - The tag specific to a data series ("seriesname" should be replaced). band - The horizontal or vertical band drawn with the xband otr yband subcommands have this tag by the actual name). xtext - The text labelling the xaxis. ytext - The text labelling hte yaxis horizontically. vtext - The text labelling the yaxis vertically.

Items such as labelled dots only have the "data" tag.

Piecharts and spiral pies:

- segment_segmentnumber - The tag identifying the segment, the string "segmentnumber" should be replaced by the actual number. This tag is used to explode the segments.

Barcharts:

Barcharts use the same tags as xy-plots (but for gradient-filled bars the data_seriesname is not used).

Histograms and isometric plots:

Currently the only tag used is "data".

Time-charts:

As these plots are scrollable, several tags are used specific to the scrolling: vertscroll, horizscroll, below, lowest, above, timeline, tline. Each item also has a tag of the form "item_number", where "number" is to be replaced by the actual sequence number of the item.

Gantt charts:

In addition to the tags described for the time-charts, the following tags are used: description, completed, summary and summarybar.

Radial charts and polar plots:

Currently the radial lines indicating the grid have no tags. The graphical objects associated with data only have the "data" tag.

Windroses:

Only the tag data_number is currently used ("number" should be replaced by the sequence number of the data, starting at 0.

Contour and isoline plots:

No tags are used.

3D plots and 3D ribbon plots:

Tags are used for the axes and for the data objects:

- data - The general tag to identify graphical objects associated with data. line - The tag used for lines created with the plotline subcommand.

Charts decorated with 3D effects:

The following tags are used to identify various types of graphical objects: platform, background, d, u, ticklines.

The text associated with the bars has no tags. The ribbon lines and areas have no tags either.

Tables:

Tags used are: frame, cellbg and celltext In addition: To implement multiple plots and charts in a single canvas, all items also get as a tag the plot/chart they belong to. This enables Plotchart to manipulate only those items.

## TODO - SOME PRIVATE NOTES

I have the following wishlist:

- Isometric plots - allow new items to be implemented easily.

- A general 3D viewer - emphasis on geometry, not a ray-tracer.

- Several improvements for boxplots:

  - Height of the box scales with the logarithm of the number of points

  - Marker line to indicate a "current" value

  - Box drawn from quantiles

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## Bugs, Ideas, Feedback

This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category plotchart of the Tklib Trackers. Please also report any ideas for enhancements you may have for either package and/or documentation. <

## Copyright

Copyright © 2013 Arjen Markus <arjenmarkus@users.sourceforge.net>