This is GDGraph, a package to generate charts, using Lincoln Stein's
GD.pm. See the documentation for some history and more information.

The latest release is available from CPAN: http://www.cpan.org/.

INSTALLATION

Requirements:

	perl 5.005
	GD >= 1.19 (recommended >= 1.23)
	GD::Text::Align (part of the GDTextUtils package)

It is very likely that it runs on 5.004, but I haven't tested it, and I
won't support it, simply because I don't have the platforms to test it
on. 5.005 has been available since July 1998, and there is not really
any excuse anymore to run anything older (5.6.0 is out! Get it!).  It is
also possible that it works with older versions of GD.  Again, I have
not tested it.

to install:

	perl Makefile.PL
	make
	make install

There are no tests. The samples directory contains examples which also
function as a test suite. To see the samples:

	make samples
	(use viewer to see samples/sample*.png or .gif)

or

	cd samples
	make
	(use viewer to see sample*.png)

The documentation available is contained in GD::Graph.pm, as pod. See it
with 

perldoc GD::Graph

after installation or 

perldoc -F Graph.pm

before installation.

TESTED PLATFORMS

I have discontinued this list, because it is too hard to maintain. There
is hardly any code in the module that could provide problems with
inter-platform portability, but you never know. I will always test the
modules against the latest stable perl (5.6.0 right now) and one older
version (5.005_03). I will not explicitly test against older versions of
Perl. I normally test against the newest version of GD, and one version
of the pre-PNG days (1.19). All of this happens on Linux.

AUTHOR

Martien Verbruggen
mgjv@tradingpost.com.au

FIRST PNG PORT as Chart::PNGgraph

Steve Bonds
sbonds@agora.rdrop.com

MOST IMPORTANT CHANGES FOR VERSION 1.30

- Added GD::Graph::Data as the preferred way of working with data sets.
  Internally all code has been changed to use these objects.
- Many, many fundamental code changes, mainly to facilitate a future
  breakup of the code into separate Data, Chart and Graphics handling.
  All of this is internal, and there are not that many new options.
  (check the CHANGES file for more information)

MOST IMPORTANT CHANGES FOR VERSION 1.20

- Namespace change to GD::Graph
- No more links to GIF or PNG. We return a GD object now. It's the
  user's responsibility to save the right format. GIFgraph and
  (hopefully) Chart::PNGgraph will become wrappers around all this
- Font support no longer part of these modules. Instead the package
  GDTextUtils is necessary.
- Some bug fixes and extra options.

MOST IMPORTANT CHANGES SINCE VERSION 1.10

- Namespace change from GIFgraph --> Chart::PNGgraph
- No longer generates GIF format images due to Unisys LZW patent
- Supports TrueType fonts

MOST IMPORTANT CHANGES SINCE VERSION 1.04

- added bar_spacing option
- added limited support for numerical X axis for equidistant X values
  (NOT for a real numerical graph!), thanks to Scott Prahl.
- routines to automatically 'guess' nice upper and lower values for
  graphs have been replaced by one written by Scott Prahl

MOST IMPORTANT CHANGES SINCE VERSION 1.03

- Added mixed type graph.
  GIFgraph::mixed
  options types and default_type
- Added callback functionality to format y values
  option y_number_format
- Added control over axis label placement
  option [xy]_label_position

MOST IMPORTANT CHANGES SINCE VERSION 1.01

- Vertical printing of X axis labels
- CHANGED DEFAULTS for zero_axis and zero_axis_only
- Fixed problems with negative values, data ranges without 0, and
  printing of the x axis labels (I hope)
- No more support for perl 5.003. Since perl 5.005 is out, and I don't
  have a 5.003 here to test all the time, I won't support it anymore.

MOST IMPORTANT CHANGES SINCE VERSION 0.91

- Legends
- Support for negative numbers
- Ticks for X axis
- line types and widths
- Allow entries in data set to be undef (to skip them)
- Changed 'zero' angle for pie charts (was right, now is front/bottom)
- Definition of colours now possible. See PNGgraph::colour::read_rgb
  for details
- See file CHANGES for more

TODO

- 3d look for graphs
- logarithmic scaling
- numerical X axes (halfway there)

BUG FIXES IN THIS VERSION

See file BUGS

NOTES FOR WIN32 and Mac

These modules _should_ work on all platforms.

Please direct any questions about the availability of these modules as
PPM packages to ActiveState. I only make this available as a standard
tar on CPAN. I have emailed ActiveState to ask what I was supposed to
do, and have, until today, not received any answers. 

THANKS

First of all. many, many thanks to Steve Bonds for adapting GIFgraph to
version 1.20 of GD (the first version that did not support GIF anymore),
and releasing it as Chart::PNGgraph. I really didn't have the time to
look at it, and he stepped in and fixed the headache that Unisys had
given me.

Others who have contributed are mentioned in the documentation for
GD::Graph in the AUTHOR section.

COPYRIGHT

GD::Graph
Copyright (c) 1999 Martien Verbruggen. All rights reserved.
Chart::PNGgraph
Copyright (c) 1999 Steve Bonds.  All rights reserved.
GIFgraph
Copyright (c) 1995-1999 Martien Verbruggen. All rights reserved.

This package is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.

I really felt like adding a clause to the copyright that excluded Unisys
and its employees from the use of any of my code, at least without a
license bought from me. I decided against it for several reasons, the
main one being that I would just feel too dirty doing that.

