plgdiplt: Get parameters that define current plot-space window 

DESCRIPTION:

    Get relative minima and maxima that define current plot-space window.
    If plsdiplt has not been called the default values pointed to by
    p_xmin, p_ymin, p_xmax, and p_ymax will be 0., 0., 1., and 1. 

SYNOPSIS:

plgdiplt(p_xmin, p_ymin, p_xmax, p_ymax)

ARGUMENTS:

    p_xmin (PLFLT *, output) :      Pointer to relative minimum in x. 

    p_ymin (PLFLT *, output) :      Pointer to relative minimum in y. 

    p_xmax (PLFLT *, output) :      Pointer to relative maximum in x. 

    p_ymax (PLFLT *, output) :      Pointer to relative maximum in y.