Gnuplot Same Data Two Axes Different Units)

Linux and Unix-Like UNIX and Linux Applications
1

I'm pretty familiar with Gnuplot, but I've never actually come across a reasonable solution to this problem and I'm hoping someone can help me out! I think it's because I don't know how to pose the problem neatly, so please bare with me. Also new to the forum....so yeah...

I have one data set (x vs y), but I'd like to have y plotted in two different units in the same plot. For instance, I want x1y1 to be x vs y and x1y2 to be x vs 1/y, so that I don't actually plot the data twice. So there would be one line, and if you looked at the left axis you'd see the y value in one unit, and the right axis would have that same value in another "unit".

Below is an example of what I'm looking for, but rotated 90degrees. Here, x2=1240/x1, and there would be one data curve that could be understood using either x1 or x2.

Any help would be awesome and greatly appreciated!

2

So, you want two different units for y? I think this will help:

set y2range [othermin:othermax]
set y2tics
set ytics nomirror
3

Thanks for the reply! But I think that's the result I'm trying to avoid....

That would mean I have to plot my dataset twice, and the left and right axes would both be linear or a logscale or whatever I chose, right?

I guess another what to phrase what I'm looking for is that I want the right axis to be a transform of the left axis's y-value. So it would look like this

y1    ->Directly Across-> y2
4-----------------------------1/4
3-----------------------------1/3
2-----------------------------1/2
1-----------------------------1
0.5---------------------------2

So, see the y2 axis has to be aligned with a specific value on y1.
The only way I can think of doing it is if I make a graph with a set scale on y1 and x1, and then add labels manually to y2. So for instance....

set xrange [0:1]
set yrange [2:4]
set label "1/2" at first 1,first 2
set label "1/3" at first 1,first 3
set label "1/4" at first 1,first 4

But I was hoping there's something more elegant and flexible....?

I'll try and upload a better image of what I'm talking about because I think my words are muddled...

4

They don't have to be both linear or log or whatever, they're independent. It won't match the second axis marking for you however, you have to make it do so yourself via formulas or what have you.

Just put two lines into the same plot command, separating with commas.