plot, given just a file containing a matrix
of grid data.
<p>

To get a scattergraph with symbols at the data points, substitute
`<font color="#82140F"><code>draw symbol</code></font>' for `<font color="#82140F"><code>draw curve</code></font>'.  Both symbols and a curve
result if both `<font color="#82140F"><code>draw curve</code></font>' and `<font color="#82140F"><code>draw symbols</code></font>' are used.
See see <a href="GettingMoreControl.html#GettingMoreControl">Getting More Control</a> for an example