Cannot use 'interp' for 'FaceColor' in patch

I want to have smoother colormap but the program said:

"Warning: Error creating or updating Patch

Error in value of property FaceVertexCData

Number of colors must equal number of vertices ".

The data are given in attached file. Please kindly help me!

s=patch(X,Y,E_t,'FaceColor','interp');

[darova]

Can you exaplain what your data represents?

s = load('plate.mat');
x = s.X;
y = s.Y;
z = s.E_t;
patch(x,y,z,'facecolor','interp')

Each vertex should have it's own color

Answer 1

[DGM]

Your patch plot only has three colors, because your CData vector E_t only contains three unique values. Maybe that's the result of some prior nearest-neighbor interpolation process that could be made continuous? I don't know exactly what your CData values mean in-context, but are you sure you're not expecting to obtain something like this?

% try to return stepped CData to a smooth linear ramp
CD=interp1([1 13 25],unique(E_t)',1:36,'linear','extrap');  
s=patch(X,Y,CD,'FaceColor','flat');

Why it's complaining about the 'interp' mode, I'm not sure. If you really need to use 'interp' mode, that question will need to be addressed.