
plgspa: Get current subpage parameters 

DESCRIPTION:

    This function is used in example 23. 

SYNOPSIS:

plgspa(xmin, xmax, ymin, ymax)

ARGUMENTS:

    xmin (PLFLT *, output) :    Pointer to variable with position of left
    hand edge of subpage in millimeters. 

    xmax (PLFLT *, output) :    Pointer to variable with position of right
    hand edge of subpage in millimeters. 

    ymin (PLFLT *, output) :    Pointer to variable with position of
    bottom edge of subpage in millimeters. 

    ymax (PLFLT *, output) :    Pointer to variable with position of top
    edge of subpage in millimeters. 
