MATLAB: How top stop for loop if value is reached

Question

Z is 2000 by 2000 matrix filled with values

I have this for loop I want it to stop when there is no change in the matrix X

so if by the 200 itration there is not a huge change in the vector 199 and 200 stop the loop

for c = 1:2000
 X(c+1,:) = X(c,:)*Z;
end

Answer 1

if( norm(X(c+1,:)-X(c,:)) < some_tolerance )
    break;
end

or perhaps

if( all(abs(X(c+1,:)-X(c,:))) < some_tolerance )
    break;
end

In the second example, some_tolerance could be a vector if you wanted to apply different tolerances to different elements