single plot with two y-axis

[oyester]

I want to plot a single time vs temperature plot with two y-axis. The first axis (on the left) is deg-C and the second axis (on the right) is deg-F. If I rescale one axis, I want the other to rescale accordingly. I tried plotting time vs deg-C, then computing time vs deg-F and plotting that too (see attached sub-VI). But then it looks like I have two plots! Is there some way to connect the two axis together so that, if one changes, then so does the other?
 

[altenbach]

You need to disable autoscaling and rewrite the max and min for the other axis whenever one axis changes. This can be done with property nodes and events, for example.

Alternatively, you could do the following:

• enable autoscale for both y axes
• disable lose fit (important!) for both y axes.
• plot the same data twice (degC), but change offset&multiplier for the the second axis to 32/1.8. (See image)
• Never change the scale manually.

Message Edited by altenbach on 05-21-2009 12:50 PM

[oyester]

Thanks for the help, but the users NEED to rescale to do whatever it is they do with this data. They will be zooming, scanning, and dragging cursors all over the place. I'm thinking about giving then a boolean that will let them toggle between the two modes as that will give me a bunch of problems that I know how to solve. But they really do want to see both scales at once.