3.6.1 Legends
Every plotting primitive function accepts a legend= keyword to allow
you to set a legend string describing that object. If you do not
supply a legend= keyword, Yorick supplies a default by repeating a
portion of the command line. For example,
will have the default legend "A: plg, cos(x), x", assuming that
the curve marker for this curve is "A". You can specify a more
descriptive legend with the legend= keyword:
| plg, cos(x), x, legend="oscillating driving force"
|
If you want the legend to have the curve marker prepended, so it is
"A: oscillating driving force" if the curve marker is "A",
but "F: oscillating driving force" if the curve marker is
"F", you can begin the legend string with the special character
"\1":
| plg, cos(x), x, legend="\1: oscillating driving force"
|
Like legends, you can specify a curve marker letter with the marker=
keyword, but if you don't, Yorick picks a value based on how many curves
have been plotted. By default, Yorick draws the marker letter on top of
the curve every once in a while – so A's mark curve A, B's mark curve
B, and so on. This is only relevant for the plg and plc commands. This
default style is ugly; use it for working plots, not polished graphics.
You should turn the markers off by means of the marks=0 keyword
for high quality plots, and distinguish your curves by line type. For
example,
| plg, cos(x), x, marks=0, type="dash",
legend="oscillating driving force (dash)"
|
In order to conserve screen space, legends never appear on your screen;
they only appear in hardcopy files. Furthermore, depending on the
graphics style, legends may not appear in hardcopy either. In
particular, the ‘vg.gs’ and ‘nobox.gs’ styles have no legends.
This is because legends are ugly. Legends take the place of a proper
figure caption in working plots. For high quality output, I expect you
to take the trouble to add a proper caption. You can use the
legends=0 keyword to the window command in order to eliminate the
legends even from those graphics styles where they normally appear.