How the replace values in one matrix by comparision with another?

Hi Matlab users,

My problem is this: I have 2 matrix of the same size let's say A=(238;132;70) and B=(238;132;70). They have different contents but matrix A has the number -99 a lot of times in it (which represents land) and matrix B has also the number -99 in it, but fewer values. How can I make so that matrix B will keep it's own values, except for the points where matrix A has -99 value, case in which it will write -99?

Best regards,

Robert.

Answer 1

[Image Analyst]

% Get a logical map of where -99 occurs in A
locations99inA = (A == -99);

% Assign ONLY THOSE locations in B to be 99
% leaving all other elements of B unchanged.
B(locations99inA) = -99;

[Robert]

You have my thanks, sir. It's working like a charm.