PGPLOT Module: PGWNAD -- set window and adjust viewport to same aspect ratio


SUBROUTINE PGWNAD (X1, X2, Y1, Y2)
REAL X1, X2, Y1, Y2

Change the window in world coordinate space that is to be mapped on
to the viewport, and simultaneously adjust the viewport so that the
world-coordinate scales are equal in x and y. The new viewport is
the largest one that can fit within the previously set viewport
while retaining the required aspect ratio.


Arguments
X1 (input) : the x-coordinate of the bottom left corner
of the viewport.
X2 (input) : the x-coordinate of the top right corner
of the viewport (note X2 may be less than X1).
Y1 (input) : the y-coordinate of the bottom left corner
of the viewport.
Y2 (input) : the y-coordinate of the top right corner of the
viewport (note Y2 may be less than Y1).