Linear y-axis and log mirror y-axis?

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Tue, 04/12/2011 - 12:43 pm

How does one make a plot where you have a linear y-axis and a logarithmic mirror y-axis? I found where to enable the mirror axis, but I do not seem to have much control over how my mirror axis is drawn.

thanks
To expand a little:

I am plotting ln(A) versus B where I have taken the ln of A before plotting (this amounts to plotting a linear trace). On the left y-axis I want units of ln(A), which ranges from 1 to, say, 10, and on the right y-axis, I want to plot units of A, on a logarithmic scale, which would range from exp(1) to exp(10). So basically, I want the mirror axis to take the exponent of the corresponding y-value. I can enable the mirror axis in graph-->modify axis, but I can't seem to add an axis with a transformation I can specify.

April 12, 2011 at 02:01 pm - Permalink

You may be able to use the Transform Axis package. To learn more about it, see the example experiment: File->Example Experiments->Graphing Techniques->Transform Axis Demo.

John Weeks
WaveMetrics, Inc.
support@wavemetrics.com

April 13, 2011 at 09:23 am - Permalink

Demo was helpful for this, though it took me a while to figure out how to implement my procedure (found it under graph-->transform axis...etc)

Last question, IGOR does not seem responsive to my 'exponential trip' preferences of my mirror axis. Shouldn't I be able to specify preferences for this mirror axis independent of my left axis? Or are there some limitations which might prevent this. Specifically, I am having trouble getting scientific notation for my mirror axis, when my regular axis ranges from 1-10. Thanks

April 13, 2011 at 02:42 pm - Permalink

keeldude wrote:
Last question, IGOR does not seem responsive to my 'exponential trip' preferences of my mirror axis. Shouldn't I be able to specify preferences for this mirror axis independent of my left axis? Or are there some limitations which might prevent this. Specifically, I am having trouble getting scientific notation for my mirror axis, when my regular axis ranges from 1-10.

The Transform Axis package uses Igor code to create the mirror axis and to establish the tick labels on that axis. The Modify Axis dialog can be used to adjust many aspects of the Transform mirror axis, but it cannot be used to affect the tick spacing or tick labels. To make certain adjustments to the Transform axis, you need Graph->Transform Axis->Modify Transform Axis. That will show a panel that I think should have a Scientific Notation checkbox on it.

John Weeks
WaveMetrics, Inc.
support@wavemetrics.com

April 14, 2011 at 09:16 am - Permalink