or code into
the z column, and do for example `<font color="#82140F"><code>draw symbol bullet color hue z</code></font>'.
The numerical color code ranges from 0 (red) through to 1, passing
through green at 1/3 and blue at 2/3.
<p>
<!-- @node   Formula Plots, Contour Plots, Scattergraphs, X-y Plots -->
<a name="FormulaPlots" ></a>
<h2>5.3: Formula Plots</h2>

There are two methods for formula graphs.
<p>
<ol>
<p>
<li> <b>Use the system yourself.</b>
Do as in this example:
<p>
<TABLE SUMMARY="Example" BORDER=