Matlab：如何为冲浪图的单个单元着色

Question

I'm trying to differentiate the color of a single cell of a surf plot based on the Z function value, in particular: X, Y are (nxm) matrix and define a surface; Z is a ones(nxm) which has some particular points set to 3 or 4 or 5

I'm trying to have a surf plot where the single grid cells with 3,4 or 5 value are colored differently then all the other surface grid cells.

here's the code and the image I'm getting (in this specific case there's only 1 Z point with value =3):

figure;surf(X,Y,Z)

In this specific example my goal is to color RED the grid cell correspondent to the peak .Is there a way to obtain it?

thnks in advance

Answer 1

As mentioned in the comments, colormap is the answer. The hard part is setting it up properly. The trick is to make the colormap larger than you need, say 10x3, make some bins inside colormap, and then scale your Z to fit into those bins. For example:

cmap(1, 1) = [0 0 0];
cmap(2:4, 1) = [0 0 1];
cmap(5:7, 1) = [0 1 0];
cmap(8:10, 1) = [1 0 0];
colormap(cmap);

This makes colormap bins, which you must fit your Z values into. You'll need to write the Z-value translation code. You need to write something that turns any element of Z which is 5, for example, into 10.

I've done this for a similar problem using images, so if you work with me we can get you an exact answer.

Answer 2

Just to be sure

colormap(jet) 

doesn't work here? One of the ways i've done this is that in the GUI, you can manually edit teh colormap values in the colormap.

Then, just print out the colormap

cmap = colormap

And then these values can be used in your function.