Re: [Plplot-general] [plplot:support-requests] #43 Colormap

[L1q1d <l1...@ya...>]

Hi Alan,I tried to apply your approach but the result is exactly the same. Due to the fact that I have to apply the transformation both on the data and the isolevel.
Any other idea?
Thanks 

    Il Venerdì 9 Giugno 2017 19:33, Alan W. Irwin <ir...@be...> ha scritto:
 

 On 2017-05-29 13:54-0000 L1q1d wrote:

> So you suggest that I transform each value of the array to it's log value

Yes, using the transformation I indicated.

> and then apply the [pl]shades?

Yes.

> Would it be quite resource consuming?

The plshades call would be no slower or faster because it is plotting
an array of cmap1 indices in the range from 0. to 1. just as per
normal.  There would be some extra time required before you make that
call to convert your array into that 0. to 1. range via the log
transformation I suggested, but that time should be negligible with
today's computer speeds.  For example, you should be able to do the
order of 100 million of such transformations per second assuming a
2GHz machine, and assuming a mathematical transformation would cost
~20 machine cycles per array value.

Anyhow, good luck with this and let us know how it goes.

Alan
__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state
implementation for stellar interiors (freeeos.sf.net); the Time
Ephemerides project (timeephem.sf.net); PLplot scientific plotting
software package (plplot.sf.net); the libLASi project
(unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
and the Linux Brochure Project (lbproject.sf.net).
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