bugGNU Octave - Bugs: bug #49363, colormap list removed but help not...


bug #49363: colormap list removed but help not fully updated

Submitted by:  None
Submitted on:  Sun 16 Oct 2016 05:14:35 PM UTC  
Category:  Octave Function Severity:  3 - Normal
Priority:  5 - Normal Item Group:  Matlab Compatibility
Status:  Fixed Assigned to:  None
Originator Name:  R.S.Carmenes Originator Email:  -email is unavailable-
Open/Closed:  Closed Release:  4.2.0-rc2
Operating System:  Any

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Mon 17 Oct 2016 03:35:24 PM UTC, comment #3: 

@Carnë: Using rgbplot was exactly what I had in mind, but I don't think there's enough time to make the change for the 4.2.0 release.

There would have to be a new m-file like plotimages.m in doc/interpreter that generated the colormap images in the four formats: .txt, .eps, .pdf, .png.  Hooking the images into the build system is also not straightforward because it goes through images.awk and the separate file images and then possibly through module.mk.  And then the docstring itself would need to be amended to have @ifinfo blocks and @image tags.  In short, I ran out of energy for all of that.  But yes, this would be a nice improvement and should get done at some point.

Long term, I think all of the image and plot functions should have visual documentation.  It's too hard to understand what something like the jet colormap is from text alone ("This colormap ranges from dark blue through blue, cyan, green, yellow, red, to dark red.").  But a picture makes it obvious.

I'll file a wish list request for all of this.

Rik <rik5>
Project Administrator
Mon 17 Oct 2016 01:45:25 PM UTC, comment #2: 

Rik, I noticed your FIXME

## @c FIXME: It would be nice to display the actual colormap as an image
## @c        in the PDF version of the documentation.

The images are easy to create, just call rgbplot with the composite option

rgbplot (viridis (), "composite")

This is actually the demo of each colormap together with the rgb profile.

Carnë Draug <carandraug>
Project Member
Sun 16 Oct 2016 07:05:36 PM UTC, comment #1: 

I added documentation to colormap.m about the available built-in maps.  See http://hg.savannah.gnu.org/hgweb/octave/rev/a918e983a943.  Fixed, closing report.

Rik <rik5>
Project Administrator
Sun 16 Oct 2016 05:14:35 PM UTC, original submission:  

Well, not sure if the following should really be called a bug, but I believe it deserves to be corrected anyway.

From octave 4.2.0, the standard colormap function does not longer accept 'list' as a parameter (till v.4.0.3 it had the effect of showing the list of built-in color maps). This change is not documented in the NEWS file, although I guess it has been done to be closer to the Matlab equivalent. Nothing wrong with this, except that now, 'help colormap' should give the names of the built-in color maps, as it does in Matlab. We cannot expect users to go though the source code as the only way to find them, isn't it?



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    Date Changed by Updated Field Previous Value => Replaced by
    2016-10-16 rik5 StatusNone => Fixed
        Open/ClosedOpen => Closed

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