[Octave-bug-tracker] [bug #54974] [octave forge] (image) incompatible results of entropy.m

[Hartmut]

Follow-up Comment #1, bug #54974 (project octave):

Here is my first proposal how to fix this (see patch file V1):
* Use imhist instead of hist. 
**This is what the Matlab help on entropy claims to do. I'm not sure this is
necessary.
* Normalize the resulting histogramm to have a sum of 1.
** This normalization is also mentioned on the Matlab help page. And when I
use this my results becomse compatible.
* Ignore the zero elements in the histogramm.
** This was also done before (as the code comment sais), but I do not
understand what entropy.m did before, the code was P += (P == 0);
* I added the example from comment #0 as new test case.

Please have a look and review this test. Any comments on the above mentioned
changes are appreciated. 

I would espacially appreciate of someone could check of the new test case is
Matlab compatible (as I am currently only assuming this). And one or two more
Matlab compatible test cases with real numbers (e.g. 5 to 10 element matrices)
could also be useful.


(file #45372)
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Additional Item Attachment:

File name: entropy_compatibility_V1.patch Size:1 KB


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