My rectangle should have a determined color represented by a value

I have 2 patch objects which should be placed with a determined color (represented by a value). I did not implement it because I dont know how it works. So the rectangle 1 should have the value 50 and the rectangle 2 should have the value 75. The colorbar should start from 0 to 100. Thank you in advance.

    v = [0 0; 1 0; 1 1; 0 1;5 5; 10 5;10 10;5 10];%Rectangle 1 and 2
    f = [1 2 3 4; 5 6 7 8];
    patch('Faces',f,'Vertices',v,'FaceColor','green')
    colorbar

Answer 1

[Stephen23]

The easiest way is to use caxis, like this:

V = [0,0;1,0;1,1;0,1;5,5;10,5;10,10;5,10];
F = [1,2,3,4;5,6,7,8];
C = [50;75];
patch('Faces',F,'Vertices',V,'FaceVertexCData',C,'FaceColor','flat')
colormap(parula)
colorbar
caxis([0,100]) % set the color limits

which generate this (you can pick whatever colormap suits you best):

TIP: learn that many many operations and functions in MATLAB are designed to be fastest and neatest without using ugly loops. Learn to read the documentation, and how to write efficient code:

https://www.mathworks.com/matlabcentral/answers/228557-experts-of-matlab-how-did-you-learn-any-advice-for-beginner-intermediate-users

[Neda]

How about if we need to change the colour of circle based on their values, and circle superimposed on the image with rectangle which does have 'Curvature',[1 1].

Answer 2

[Thorsten]

50 and 75 are not valid colorvalues in Matlab. Valid is an RGB triplet in the range [0, 1]. So I assumed that 50 and 75 is an index into a colormap. I choose 'gray', but you can any other valid colormap, like 'parula' or 'jet', for example:

Nfaces = 2;
facecolind = [50 70];
cmap = gray(100);

for i = 1:Nfaces
  patch('Faces',f(i,:),'Vertices',v,'FaceColor', cmap(facecolind(i),:))
end

colormap(cmap)
h = colorbar
h.TickLabels = h.Ticks*100

[Philipp Mueller]

thank you for your answer. I mean the value 50 should be green and 75 is higher so it should be more red. I have several rectangles. Rectangles with a low value should be blue or green and rectangles with a high value should be orange or red. It depends on the value. It should work (filling) automatically

[Adam]

Sounds like you want the jet colourmap then. You could create your own to be more to your taste, but jet does run from blue through green up to red.

[Philipp Mueller]

thank you so much