I’m trying to solve a problem. The following is my code:

cvx_begin

variable w nonnegative;

variable x(n,1) complex;

minimize( norm(x,1) );

subject to

W_matrix(1:m,1:m) = w;

W_matrix(num1, = 1;

W_matrix = diag(diag(W_matrix));

norm(W_matrix*(y-A*x),2) <= u;

cvx_end

where w and x are variables, W_matrix is a diagonal matrix with 1 or w of the diagonal elements, y is a given vector with positive values, m and n is a given positive constant, num1 is a given positive array, A is a given matrix and u is a given positive value.

But it pop up this error massage:

Error using cvx/mtimes (line 126)

Disciplined convex programming error:

Only scalar quadratic forms can be specified in CVX

Error in test1w (line 71)

norm(W_matrix*(y-A*x),2) <= u;

I can’t find out why, please help me. Thank you so much.