# how to plot a single valued function over a triangulated surface?

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Commented: ahmad on 25 Apr 2016
I have a finite element mesh [t,p] for a surface in 3D, where t is the triangles and p is the (x,y,z) coordinates of the vertices. For instance the mesh for the unit sphere from http://persson.berkeley.edu/distmesh/. I'm using the Matlab command patch('Faces',t,'Vertices',p,'edgecol','r'); to visualize this mesh. The question is how to plot a function defined over this triangulated surface?

Mike Garrity on 25 Apr 2016
You can do it with patch. You'll just want to set FaceColor to interp and set the FaceVertexCData to to value of your function.
But you might find it easier to use the trisurf function. Here's a simple example:
npts = 100;
x = 2*randn(npts,1);
y = 2*randn(npts,1);
z = peaks(x,y);
c = z;
tri = delaunay(x,y);
h = trisurf(tri,x,y,z,c,'FaceColor','interp');
colormap(parula(12))
axis tight
Thanks a lot. That's exactly what I was looking for, i.e., setting FaceColor to interp and FaceVertexCData to the value of the function. However, I'm not sure if trisurf would give the required answer.