Is it possible to plot two curves, with two corresponding axes in gnuplot, each of which has a different scale?
For example, y=x**2 and y=x**4 in the same graph (they vary enough to be "uncomfortable" when plotted with the same scale).
33
votes
@Kazark - Would you mind explaining what was the point of that edit? To make the question non-compatible with both answers, or?
- Rook
@Idigas There was of course no intention of obscuring the question. If you think I have done so, you can of course roll back the edit.
- Keith Pinson
@Kazark - So why the edit then?
- Rook
Why not to accept one of answers?
- brownian
2 Answers
51
votes
You can have the axes handled automatically without you having to scale them yourself and keep auto-scaling:
set terminal jpeg
set output 'graph.jpg'
set xrange [-10:10]
set ytics 10 nomirror tc lt 1
set ylabel '2*x' tc lt 1
set y2tics 20 nomirror tc lt 2
set y2label '4*x' tc lt 2
plot 2*x linetype 1, 4*x linetype 2 axes x1y2
12
votes
It is possible to set different ranges for y and y2 (the right axes), and even to set the color of the labels/tics independently.
Then we simply divide the second function by 2 (or something appropriate) and set the colors... as in this example:
set xrange [-10:10]
set yrange [-20:20]
set y2range [-40:40]
set ytics 10 nomirror tc lt 1
set ylabel '2*x' tc lt 1
set y2tics 20 nomirror tc lt 2
set y2label '4*x' tc lt 2
plot 2*x linetype 1, 4*x/2+.5 linetype 2
