Question

I’ve got a matrix A with the dimensions m X n. For every column i (i > 0and i <= n) I want to flip a coin and fill the whole column with 0 values with probability p. How can this be accomplished in MATLAB?

Example:

A = [1 2 3 4; 5 6 7 8] and p = 0.5 could result in
A’ = [1 0 3 0; 5 0 7 0]

Answer 1

You can use the function rand() to generate an array of uniformly distributed random numbers, and use logical indexing to select colums where that array is less than p:

A = [1 2 3 4; 5 6 7 8];
p = 0.5;

A(:, rand(size(A,2), 1)<p) = 0

A =

     0     2     0     0
     0     6     0     0