八度，如何保存情节图？

Question

I need to save a plot. This is my code that I don't know why it does not work.

hold on;
plot(x1, y2)
plot(x1, y2)
print -djpg image.jpg

The plot in output on screen is correct, but the output in the file is different: it saves only an empty plot image without my points.

This is my output in the file:

Answer 1

I just had the same issue with the latest Octave (3.8.1). This issue comes from GhostScript, not Octave. There's a bug with the management of fonts.

To make sure, check in your console after you try to print if this error is outputted (along with a lot more infos):

GPL Ghostscript 8.63: Unrecoverable error, exit code 1

If that's the case, then try this:

set (0, "defaultaxesfontname", "Helvetica") % this is the line to add BEFORE plotting
hold on;
plot(x1, y2)
plot(x1, y2)
print -djpg image.jpg

This will fix the problem by setting a font that GhostScript can handle without any issue. Note that if you already plotted the figure, you will have to close it and replot it after setting defaultaxesfontname.

Source: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=710272