dinates, is specified in terms of the cartesian coordinates of
the lower-left corner (`<font color="#82140F"><code>.xleft.</code></font>', `<font color="#82140F"><code>.ybottom.</code></font>') and upper-right
corner (`<font color="#82140F"><code>.xright.</code></font>', `<font color="#82140F"><code>.ytop.</code></font>').  If the `<font color="#82140F"><code>box</code></font>' option is not
specified, this geometry can be specified with either `<font color="#82140F"><code>read x grid</code></font>'
or `<fo