Colormap setting the colors i want

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Tiago Dias
Tiago Dias on 29 Jun 2018
Commented: Tiago Dias on 2 Jul 2018
Hello, So I discovered Colormap, and I want to draw a Color map of a matrix A I got that has ranges from 0 to 1. But I don't want to use the colours Matlab provides (jet for example), I want to create my own. Green for 0, Red for 1, and in between a mix from red, yellow for 0.5, orange and then red. A bit like Excel does.
colormap('jet');
imagesc(A);
colorbar;
Thanks
  2 Comments
Tiago Dias
Tiago Dias on 29 Jun 2018
I would like to create one has simples as Excel, red to green or green to red, with orange for middle values

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Accepted Answer

Stephen
Stephen on 29 Jun 2018
Edited: Stephen on 29 Jun 2018
You can easily adjust colormaps by using the colormapeditor:
As an alternative to defining the colormap matrix "by hand", you could use one of the colormap generators/creators on MATLAB FEX:
Some of them allow you to create a whole colormap from just a few RGB colors, e.g.:
  3 Comments
Tiago Dias
Tiago Dias on 2 Jul 2018
Nevermind, i was typing it wrong
colormap(mymap)
works perfect, thanks for your first link it helped me a lot :)

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More Answers (2)

Image Analyst
Image Analyst on 29 Jun 2018
Create your own colormap then assign values in whatever way you want:
numColors = 256; % Whatever....
myColorMap = zeros(numColors, 3); % Col1 = red, col2 = green, col3 = blue.
myColorMap(row1:row2, 1); % Set red values however you want.
... etc...
% Apply it.
colormap(handlesToMyAxes, myColorMap);
% Show bar
colorbar;
  9 Comments
Tiago Dias
Tiago Dias on 2 Jul 2018
I got a lot of values from 0 to 1, and my objective is to creat 10 intervals of colours 0,0.1,0.2,0.3,...,1.0 from red to green like excel does.

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Wooshik Kim
Wooshik Kim on 29 Jun 2018
Edited: Wooshik Kim on 29 Jun 2018
You can set your own colormap with the following
mymap = [0 0 0.3 0 0 0.4 0 0 0.5 0 0 0.6 0 0 0.8 0 0 1.0]; colormap(mymap)
where each column corresponds to Red, Green, Blue intensities between 0 and 1.
The following page might be helpful.

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