
plwind: Specify world coordinates of viewport boundaries 

DESCRIPTION:

	Sets up the world coordinates of the edges of the viewport. 

SYNOPSIS:

plwind(xmin, xmax, ymin, ymax)

ARGUMENTS:

    xmin (PLFLT, input) :     The world x coordinate of the left-hand edge
        of the viewport. 

    xmax (PLFLT, input) :     The world x coordinate of the right-hand edge
        of the viewport. 

    ymin (PLFLT, input) :     The world y coordinate of the bottom edge of
        the viewport. 

    ymax (PLFLT, input) :     The world y coordinate of the top edge of the
        viewport. 
