
plsvpa: Specify viewport in absolute coordinates 

DESCRIPTION:

	Alternate routine to plvpor for setting up the viewport.  This routine
	should be used only if the viewport is required to have a definite
	size in millimeters.  The routine plgspa is useful for finding out the
	size of the current subpage. 

SYNOPSIS:

plsvpa(xmin, xmax, ymin, ymax)

ARGUMENTS:

    xmin (PLFLT, input) :     The distance of the left-hand edge of the
        viewport from the left-hand edge of the subpage in millimeters. 

    xmax (PLFLT, input) :     The distance of the right-hand edge of the
        viewport from the left-hand edge of the subpage in millimeters. 

    ymin (PLFLT, input) :     The distance of the bottom edge of the
        viewport from the bottom edge of the subpage in millimeters. 

    ymax (PLFLT, input) :     The distance of the top edge of the viewport
        from the bottom edge of the subpage in millimeters. 
