PGPLOT Module: PGSVP -- set viewport (normalized device coordinates)


SUBROUTINE PGSVP (XLEFT, XRIGHT, YBOT, YTOP)
REAL XLEFT, XRIGHT, YBOT, YTOP

Change the size and position of the viewport, specifying
the viewport in normalized device coordinates. Normalized
device coordinates run from 0 to 1 in each dimension. The
viewport is the rectangle on the view surface "through"
which one views the graph. All the PG routines which plot lines
etc. plot them within the viewport, and lines are truncated at
the edge of the viewport (except for axes, labels etc drawn with
PGBOX or PGLAB). The region of world space (the coordinate
space of the graph) which is visible through the viewport is
specified by a call to PGSWIN. It is legal to request a
viewport larger than the view surface; only the part which
appears on the view surface will be plotted.


Arguments
XLEFT (input) : x-coordinate of left hand edge of viewport, in NDC.
XRIGHT (input) : x-coordinate of right hand edge of viewport,
in NDC.
YBOT (input) : y-coordinate of bottom edge of viewport, in NDC.
YTOP (input) : y-coordinate of top edge of viewport, in NDC.