Is 2d colormap supported by matlab?

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Ray Lee 2017-8-28

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回答： Image Analyst 2017-8-28

采纳的回答： Image Analyst

Generally in matlab we use 1D gradient colormap as

How do we use colormap like this

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Ray Lee 2017-8-28

@ImageAnalyst Yes, you are right. The color and the brightness represent two data sets. I found an example here

Stephen23 2017-8-28

编辑：Stephen23 2017-8-28

@Ray Lee: as an aside, you really really should avoid using the awful JET/RAINBOW colormap. The reasons have been discussed in detail on the internet, and also here:

https://blogs.mathworks.com/steve/2014/10/13/a-new-colormap-for-matlab-part-1-introduction/

https://blogs.mathworks.com/steve/2014/10/20/a-new-colormap-for-matlab-part-2-troubles-with-rainbows/

https://blogs.mathworks.com/steve/2014/11/12/a-new-colormap-for-matlab-part-3-some-reactions/

https://blogs.mathworks.com/steve/2014/12/10/a-new-colormap-for-matlab-part-4-the-name/

The new default colormap parula is a significant improvement, and you can also find other colormaps on FEX, ready for you to download:

https://www.mathworks.com/matlabcentral/fileexchange/?term=perceptually+uniform

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Image Analyst 2017-8-28

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https://ww2.mathworks.cn/matlabcentral/answers/354315-is-2d-colormap-supported-by-matlab#answer_279485

在 MATLAB Online 中打开

Ray, if you have two parameters, air pressure and frequency, you can't use a colormap and you'll have to create an RGB image instead. You can get the color like this, assuming air pressure and frequency are the row and column of your "colormap" image:

for col = 1 : columns
    for row = 1 : rows
        thisColor = colormap2D(frequency(row, column), pressure(row, column), :) % A 1-by-3 vector
        rgbImage(row, column, :) = thisColor;
    end
end

So it has a pressure image and a frequency image. For exvery pixel, it gets the pressure and frequency and uses those as an index to get the desired color for that pixel, which it assigns to a new RGB image.