GCOLOR="#efefef" WIDTH="100%">
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<TD>
<PRE>
<font color="#82140F">
open file.dat
read .num.
read columns .num. x y
</font></PRE>
</TD>
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<p>
You can define variables within the Gri program:
<p>
<TABLE SUMMARY="Example" BORDER="0" BGCOLOR="#efefef" WIDTH="100%">
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<PRE>
<font color="#82140F">
.num. = 10
read columns .num. x y
</font></PRE>
</TD>
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</TABLE>
<p>
You can get variables interactively from the user, using the
`<font color="#82140F"><code>query</code></font>' command.  (