Re: setting axis limits for contour plots

On Tue, 21 Nov 2006, Juerg Schmidli wrote:

> Hi all
>
> I have a problem setting the axis limits with contour plots. I want
> to compare, for instance, time-height plots of wind speed from
> observations with simulation results, where the observations are
> not complete. Say for example, that the observations are only available
> for the first 12 hours, but that I want to create a plot covering the
> entire day.
>
> I tried to set the resources trXMinF, trXMaxF, trYMinF, trYMaxF to
> the corresponding values, but I get the message
> "warning:ContourPlotInitialize: current transformation requires trYMinF
> to be within data coordinate range: resetting"
>
> I included a short test script to illustrate the problem.
>
> How can I set the plotting window to a region which is larger than
> that covered by the data?
>
> Any help is greatly appreciated
>
> Thanks,
> Juerg

Hi Juerg,

When you have the following two lines in your pyngl script:

res.sfXArray = t
res.sfYArray = z

this causes the internal code to signal that you have "irregular" X
and Y axes, even if t and/or z are regularly spaced. When you are in
"irregular" mode, then it will not allow you to extrapolate axes
values that are outside the limits of t and z.

There are a couple of solutions here, one a bit easier than the other.
The easier method you can use if t and z are regularly
spaced. Luckily, this is the case with your code.

Instead of setting the sfXArray and sfYArray arrays, you can
set the min/max values via:

   res.sfXCStartV = min(t)
   res.sfXCEndV = max(t)
   res.sfYCStartV = min(z)
   res.sfYCEndV = max(z)

PyNGL will then assume that your values are regularly spaced, and you
should then be able to set the tr* resources.

Let me know if this doesn't work for you.

--Mary
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Received on Tue Nov 21 2006 - 08:40:49 MST