How to use variable Y in cvx Nonconvex Nov 24, 2013 S Sujata Nov 24, 2013 #1 if Y=vec(X)conj(transpose(X)) and X is a NN matrix. sorry sir it is Y=vec(X)conj(transpose(vec(X))) and X is NN matrix. M Michael C. Grant Nov 24, 2013 #2 This expression isn’t well posed. vec(X) is N^2\times 1, and conj(transpose(X)) is N\times N.