%N pgpap %F $MIR/src/pgpap.f
%D Change the size of the view surface
%B
      SUBROUTINE PGPAP (WIDTH, ASPECT)
      REAL WIDTH, ASPECT

 This routine changes the size of the view surface ("paper size") to a
 specified width and aspect ratio (height/width), in so far as this is
 possible on the specific device. It is always possible to obtain a
 view surface smaller than the default size; on some devices (e.g.,
 printers that print on roll or fan-feed paper) it is possible to 
 obtain a view surface larger than the default.

 This routine should be called either immediately after PGBEG or
 immediately before PGPAGE. The new size applies to all subsequent
 images until the next call to PGPAP.

 Arguments:
  WIDTH  (input)  : the requested width of the view surface in inches;
                    if WIDTH=0.0, PGPAP will obtain the largest view
                    surface available consistent with argument ASPECT.
                    (1 inch = 25.4 mm.)
  ASPECT (input)  : the aspect ratio (height/width) of the view
                    surface; e.g., ASPECT=1.0 gives a square view
                    surface, ASPECT=0.618 gives a horizontal
                    rectangle, ASPECT=1.618 gives a vertical rectangle.
