How to assign different colormaps to different stacked bars

I have a defined variable of 2x12, and would like to create a stacked bar plot but using two different colormaps defined below:

c1=[0 0 1];%B
c2=[1 1 1];%W
c3=[1 0 0]; %R
n3=11;
n4=53;
cmap1=[linspace(c1(1),c2(1),n3);linspace(c1(2),c2(2),n3);linspace(c1(3),c2(3),n3)];
cmap1(:,end+1:end+n4)=[linspace(c2(1),c3(1),n4);linspace(c2(2),c3(2),n4);linspace(c2(3),c3(3),n4)];

n5=42;
n6=22;
cmap2=[linspace(c1(1),c2(1),n5);linspace(c1(2),c2(2),n5);linspace(c1(3),c2(3),n5)];
cmap2(:,end+1:end+n6)=[linspace(c2(1),c3(1),n6);linspace(c2(2),c3(2),n6);linspace(c2(3),c3(3),n6)];

I don't know how to apply these two different colormaps on the two stacked bar plots without one overwriting the other, so I always end up with the same colormap for both stacks. Any suggestions?

Thanks!

Answer 1

[Walter Roberson]

Look in the File Exchange for freezeColors().

Draw the first item and apply its colormap. Use freezeColors() to convert it to RGB from pseudocolor. Now you can draw the second item and apply its colormap because the first item is no longer using colormaps.

[Tasi]

Thank you for your answer. Unfortunately, I am using version 2017a and it doesn't have freezeColors function.

[Walter Roberson]

Look in the File Exchange for freezeColors().

Like https://www.mathworks.com/matlabcentral/fileexchange/7943-freezecolors---unfreezecolors

[Tasi]

I downloaded the freezeColors.m but I still have a problem of overwriting of the old colormap. I even try separating the two in the subplots. So I have var1 with first column of values and second of NANs. I then define a second variable with first column of NANs and second of different values. I then write:

subplot(1,2,1)
bar(var1,'stacked')
colormap(cmap1')freezeColors
subplot(1,2,2)
bar(var2,'stacked')
colormap(cmap2')

... and this is where I get the old cmap1 on the first stack overwritten by the new cmap2 so now both stacks have the same colormap.

[Walter Roberson]

Which MATLAB release are you using? R2014a and before only have one colormap per figure -- but even that should not matter with freezeColors()

Ah, in R2017b when I use freezeColors I see

Error using matlab.graphics.chart.primitive.Bar/set
Error setting property 'CData' of class 'Bar':
Value must be a scalar, vector or array of numeric type
Error in freezeColors (line 157)
        set(hh,'CData',realcolor);

I will need to think about that.

[Walter Roberson]

b = bar(var1, 'stacked');
for K = 1 : length(b); b(K).FaceColor = cmap1(:,K).'; end

and likewise with the second variable.

[Tasi]

I am trying to adjust this code, but it is still not doing it. I am trying to figure out why that is. Thanks so much for your help.