Excluding values from surf plot-CodePudding

Suppose we have a surf plot like this:

A = round(peaks,0);
surf(A)

Is there any way to modify the colormap so that it excludes all values in A that are equal to 0, as if they were NaN?

Colouring 0's as white without affecting the rest of the colourmap would be another acceptable solution.

CodePudding user response：

You mentioned the solution: set all 0s to nan:

A = round(peaks, 0);
A(A==0)=nan;  % in-place logical mask on zero entries
surf(A)
% The same, but with a temporary variable, thus not modifying A
B = A;
B(B==0) = nan;
surf(B)

Results in (R2007a):

If you do not want to modify A or use a temporary variable, you'll need to "cut a hole" in your colour map

A = round(peaks);

unique_vals = unique(A);  % Get the unique values
cmap = jet(numel(unique_vals));  % Set-up your colour map
zero_idx = find(unique_vals==0);  % find 0 index
cmap(zero_idx,:) = 1;  % all ones = white. Nan would make it black

surf(A, 'EdgeColor', 'none')
colormap(cmap)  % Use our colour map with hole

NB: the 'EdgeColor', 'none' pair is used to remove the edges of each patch, such that you don't see a "grid" where the values are 0.