Organization of plots in the Manual

[Michael D Godfrey]

I was editing a few typos in plot.txi and noticed that
the text which is indicated to have generated a plot
is given in plot.txi as, for example:
@example
@group
x = -10:0.1:10;
plot (x, sin (x));
@end group
@end example
==========================
But, the actual code that creates the plot is in plotimages.m
Thus, there is a duplication of code which should be kept in
sync.  This is error prone, and there are a few errors.

Can anyone think of a convenient way to have one source of
plot commands for both plotting and inclusion in the Manual
text?

Michael