I'll illustrate for an nxn where n = 3, and repeat 2 times:
% Set the random number generator seed, for repeatability here
rng default
% Size of matrix
n = 3;
% Starting matrix -- use your real data instead
M = magic(n);
% Loop two times
for ii = 1:2
% Chose random element index (using linear index)
rndIdx = randi(n*n);
% Change the random element to a random value from 1:1000 (which I guess is what you want?)
M(rndIdx) = randi(1000)
% Put save step here, if you want to save each one
end
This code keep going forward from the original matrix, changing elements one at a time (but sometimes it could overwrite the same location more than once). You'll need to adjust the code if you want to start from M, save, start from original M again, etc.
But hopefully you get the idea.
