If a matrix contains 1's and 0's ,i would like to get only those 1's and want to take avg values of those corresponding intensity values

If a matrix contains 1's and 0's ,i would like to get only those 1's and want to take avg values of those corresponding intensity values

[Jan]

Which intensity values? The average of the ones in a matrix is 1.0, so what is "corresponding" here?

Answer 1

[KSSV]

Let a be your vector which have 0 and 1.

% get indices of 1 
idx = a(a==1);

Let b be your intensity values corresponding to a.

% extract inentisity values of positions 1 
b_1 = b(idx);

Answer 2

[Image Analyst]

If matrix1 is your matrix of 0's and 1's, and matrix2 is your intensity matrix, you can get the mean intensity of matrix2 only where the values of matrix1 are 1 like this:

theMean = mean(matrix2(matrix1));