My MATLAB code is shown below:

The error is:

Disciplined convex programming error:

Cannot perform the operation: {convex} .* {real affine}

Error in ==>

norm_sum_col(j,i) = w(:,i)’ * h_k(:,j) * h_k(:,j)’ * w(:,i) * lambda(j);

Would anyone give me some idea about it?