MATLAB Answers

saving edited colormap data

257 views (last 30 days)
Natan
Natan on 9 Jul 2015
Edited: Walter Roberson on 6 Jun 2018
After editing an existing colormap with the colormapeditor, I want to save it. The documentation states that I should do something like:
mycmap = get(fig,'Colormap');
However, the saved colormap, mycmap, has the original colormap data not the eddited one. Here's a minimal example:
imagesc(peaks(10));
colormap(hot(6))
Now go into the figure's gui colormap editor using >Edit>Colormap and only change yellow to blue. Now after that press Apply see that indeed the figure has changed. Now write on the command line:
mycmap = get(gcf,'Colormap')
mycmap =
0.5000 0 0
1.0000 0 0
1.0000 0.5000 0
1.0000 1.0000 0
1.0000 1.0000 0.5000
1.0000 1.0000 1.0000
there no "blue" ([0 0 1]) color. Interestingly, when the figure is saved the colormap is saved with it, but for some reason I cant access the edited colormap. What am I doing wrong? (I'm using Matlab 2014b)

  0 Comments

Sign in to comment.

Accepted Answer

Natan
Natan on 12 Oct 2015
It looks like the colormap is now associated with the axes rather than the figure. So,
cmap = colormap(gca);
will retrieve the edited map.

  3 Comments

Walter Roberson
Walter Roberson on 12 Oct 2015
So I provided the correct solution but don't even get a vote? :(
Natan
Natan on 28 Dec 2015
saying "So use gca" is a very partial answer. I had to go and investigate how one should use gca, and that was far from the regular way gca is usually used (i.e. set(gca...) ). that is why I felt I had to write the full answer.
Zhao-Yang CHAI
Zhao-Yang CHAI on 3 May 2018
Very useful! I have met the same problem and maybe it's a bug. It's strange that the colormaps of gca and gcf are different.

Sign in to comment.

More Answers (2)

Walter Roberson
Walter Roberson on 10 Oct 2015
Starting in R2014b, colormaps are per-axes rather than per-figure. So use gca (or some other way of identifying the axes) instead of gcf .

  2 Comments

hamed amini
hamed amini on 26 May 2018
mycbar= get(gca,Colormap'); % this works
set(gcf,'Colormap',mycbar); %this works
set(gca) does not work in R2017a. This does not sound right and is confusing.
Walter Roberson
Walter Roberson on 6 Jun 2018
?
set(gca, 'Colormap', mycbar)
works

Sign in to comment.


Sean de Wolski
Sean de Wolski on 9 Jul 2015
Is gcf, the same as fig?

  6 Comments

Show 3 older comments
Natan
Natan on 9 Jul 2015
well, that's not surprising. I just hope other people would still look at this question, even though there seems to be an "answer" though it is still not answered.
Ken
Ken on 10 Oct 2015
I have the same problem! This is a bug that needs fixing, or a good explaination
Natan
Natan on 12 Oct 2015
I found the answer, see below...

Sign in to comment.

Sign in to answer this question.

Products