Plot colouring from a value?
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Hello,
I'm looking at how to colour a plot from a certain value on the vertical axis. I have been looking at the documentation but I can only find how to create area plots with colours, or how to change the plot lines.
Any ideas?

Thank you very much!
1 Comment
Jonas
on 27 Apr 2021
so you want points with a certain y value be of different color than other values? you could just seperate the points before plotting into values with specific y value and plot them one after the other?
Answers (1)
DGM
on 27 Apr 2021
If you're trying to set regions of the plot background, consider the example:
% example data
t = linspace(0,8.5*pi,100);
f = -t.^2.*sin(t) + t.^2;
h1 = plot(t,f); % plot first so that x,y limits are known if not explicitly set
xl = get(gca,'xlim');
yl = get(gca,'ylim');
hold on; grid on
% create colored regions
patch(xl([1 2 2 1]),kron([800 yl(2)],[1 1]),'black','edgealpha',0,'facecolor',[0.985 0.471 0.453],'facealpha',0.2);
patch(xl([1 2 2 1]),kron([500 800],[1 1]),'black','edgealpha',0,'facecolor',[0.94 0.969 0.425],'facealpha',0.2);
patch(xl([1 2 2 1]),kron([yl(1) 500],[1 1]),'black','edgealpha',0,'facecolor',[0.13 0.723 0.419],'facealpha',0.2);
% throw a label in a region like the example shows
text(2,1000,'Oh No!','fontsize',14,'fontweight','bold')
uistack(h1,'top') % move the plot back to the top

2 Comments
DGM
on 28 Apr 2021
If the answer satisfies your needs, please click 'accept' so your question gets categorized accordingly.
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