Surf plot of minimum values of four matrices

Hello, I have the following 4 matrices:

ZCV=[1 2 1 2;6 5 2 8;3 5 9 4; 11 2 0.5 6]; % yellow surf
ZBTmod=[5 2 9 4;1 2 0.2 9;10 9 5 7; 0.6 5 8.3 4]; % cyan surf
ZCD=[2 8 9 5;1 0.2 5 8;6 2 5 8; 0.6 9 8 7]; % red surf
ZCB=[6 2 6 2;2.3 6 7.3 5;4 4 4 6; 0.1 2 8 6]; % blue surf

I would like to plot a surf of minimum values of these 4 matrices with view (0 90) such that the color of a portion of the surf is consistent with the color indicated above. Attached is a sketch of my idea:

Answer 1

[DGM]

I don't know how you intend to get that plot from that data, but maybe your actual data has more resolution.

ZCV=[1 2 1 2;6 5 2 8;3 5 9 4; 11 2 0.5 6]; % yellow surf
ZBTmod=[5 2 9 4;1 2 0.2 9;10 9 5 7; 0.6 5 8.3 4]; % cyan surf
ZCD=[2 8 9 5;1 0.2 5 8;6 2 5 8; 0.6 9 8 7]; % red surf
ZCB=[6 2 6 2;2.3 6 7.3 5;4 4 4 6; 0.1 2 8 6]; % blue surf

% stack the arrays
ZZ = cat(3,ZCV,ZBTmod,ZCD,ZCB);

% find the minimum values and the corresponding source index
[Z idx] = min(ZZ,[],3);

% if all that's desired is a flat-colored image
% then there's no need for surf() or the Z data
% just generate an image from the indices and the colormap
CT = [1 1 0;
    0 1 1;
    1 0 0;
    0 0 1];
outpict = ind2rgb(idx,CT);

% image has the same size as the Z data
imshow(outpict)

[Gaetano Pavone]

Thanks, I don't want an image. I want a plot. Maybe contourf can be useful. But I can't define the colours.

[Gaetano Pavone]

I used this modified version of your code:

ZZ = cat(3,ZCV,ZBTmod,ZCD,ZCB);
[Z,idx] = min(ZZ,[],3);
lengthCV=[1:9];
[X,Y] =meshgrid(3:20,lengthCV);
surf(X,Y,idx)
view(axes1,[0 90]);

This is the result:

I want to assign the color matrix according to the previous color's definition. How can I do this?

[Gaetano Pavone]

I solved by adding:

CT = [1 1 0;
    0 1 1;
    1 0 0;
    0 0 1];
colormap(CT)

However the legend is not consistent with the colors. How can I fix it?

Answer 2

[Steven Lord]

Create the four surfaces.

ZCV=[1 2 1 2;6 5 2 8;3 5 9 4; 11 2 0.5 6]; % yellow surf
surf(ZCV, FaceColor = "y")
hold on
ZBTmod=[5 2 9 4;1 2 0.2 9;10 9 5 7; 0.6 5 8.3 4]; % cyan surf
surf(ZBTmod, FaceColor = "c")
ZCD=[2 8 9 5;1 0.2 5 8;6 2 5 8; 0.6 9 8 7]; % red surf
surf(ZCD, FaceColor = "r")
ZCB=[6 2 6 2;2.3 6 7.3 5;4 4 4 6; 0.1 2 8 6]; % blue surf
surf(ZCB, FaceColor = "b")

Look at the axes from below.

view([0 0 -1]) % or view(0, -90)

[Gaetano Pavone]

Your solution is simpler but the y-axis is inverted

[DGM]

You can just do

set(gca,'ydir','reverse')

If my answer wasn't what you wanted, you can always change which answer you accept.