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Fill area between plot and the 0-line?
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Hi,
I want to plot some data to show a difference to a reference value and i want that the curve above zero gets filled red and the area of the plot below zero gets filled with blue.
How do i do that?
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Accepted Answer
Akira Agata
on 1 Jun 2020
The following is an example:
% Sample data
x = linspace(0,4*pi,1000);
y = sin(x);
% Extract positive and negative part
yp = (y + abs(y))/2;
yn = (y - abs(y))/2;
% Plot the data using area function
figure
area(x,yp,'FaceColor','r')
hold on
area(x,yn,'FaceColor','b')
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/307403/image.png)
More Answers (2)
the cyclist
on 31 May 2020
3 Comments
the cyclist
on 31 May 2020
The way I would do it is to use your data points to define polygons that are above zero, and polygons that are below zero, and then use patch or fill, to fill them in.
Image Analyst
on 1 Jun 2020
For a more general situation, see the FAQ: https://matlab.fandom.com/wiki/FAQ#How_do_I_shade_the_region_between_two_curves.3F
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