%N pgqvsz %F $MIR/src/pgqvsz.f
%D Inquire size of view surface
%B
      SUBROUTINE PGQVSZ (UNITS, X1, X2, Y1, Y2)
      INTEGER UNITS
      REAL X1, X2, Y1, Y2

 This routine returns the dimensions of the view surface (the maximum
 plottable area) of the currently selected graphics device, in 
 a variety of units. The size of the view surface is device-dependent
 and is established when the graphics device is opened. On some 
 devices, it can be changed by calling PGPAP before starting a new
 page with PGPAGE. On some devices, the size can be changed (e.g.,
 by a workstation window manager) outside PGPLOT, and PGPLOT detects
 the change when PGPAGE is used. Call this routine after PGPAGE to 
 find the current size.

 Note 1: the width and the height of the view surface in normalized
 device coordinates are both always equal to 1.0.

 Note 2: when the device is divided into panels (see PGSUBP), the
 view surface is a single panel.

 Arguments:
  UNITS  (input)  : 0,1,2,3 for output in normalized device coords, 
                    inches, mm, or device units (pixels)
  X1     (output) : always returns 0.0
  X2     (output) : width of view surface
  Y1     (output) : always returns 0.0
  Y2     (output) : height of view surface
