MATLAB: Pie chart color assignment

image processingpie chartstatistics

I am trying to make a pie chart of two quantities. Using a colormap, I have assigned two different colours to each of the quantities – one is green and the other one red.
In one of the charts the first quantity is at 100%, while in the other chart the second quantity is at 100%. So one chart has to be entirely red, and the other one entirely green. However, both charts always appear with the same colour:
And here is what I am trying to obtain:
So what is wrong here and how can we fix the problem?
Here is my code:
subplot(211)
x=[1,0];
pie(x)
colormap([0 0.70 0; 1 0.1 0]);
subplot(212)
x=[0,1];
pie(x)
Any help is greatly appreciated.

Best Answer

Pie ignores non-positive values. Therefore, both arrays you declare are treated as the same to pie, and are interpreted as [1]. This is why you see that pie is treating both inputs as being 100% red.
One workaround you could use would be to call colormap twice, once after each plot. This would give you the desired colors. Other than that, it seems you would need to input some non-zero information into the pie chart. Otherwise, they will be ignored.
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