
plvpas: Specify viewport using coordinates and aspect ratio 

DESCRIPTION:

	Device-independent routine for setting up the viewport.  The viewport
	is chosen to be the largest with the given aspect ratio that fits
	within the specified region (in terms of normalized subpage
	coordinates).  This routine is functionally equivalent to plvpor when
	a ``natural'' aspect ratio (0.0) is chosen.  Unlike plvasp, this
	routine reserves no extra space at the edges for labels. 

SYNOPSIS:

plvpas(xmin, xmax, ymin, ymax, aspect)

ARGUMENTS:

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

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

    ymin (PLFLT, input) :     The normalized subpage coordinate of the
        bottom edge of the viewport. 

    ymax (PLFLT, input) :     The normalized subpage coordinate of the top
        edge of the viewport. 

    aspect (PLFLT, input) :    Ratio of length of y axis to length of x
        axis. 
