CVX error:Conversion to double from cvx is not possible

1

Hi ALL,

I have a trouble. This my code

Blockquote
cvx_begin sdp
expression X_new(4,4,S,K)
variable Omega_new(S,K)

                sum_omega = sum(sum(SubcarrierAllocation_old .* Omega_new));
                
                minimize sum_omega
                subject to
                for k = 1:K
                    for s = 1:S
                        X_new(:,:,s,k) = [Omega_new(s,k)/2*eye(2)  eye(2); eye(2)  Power_old(s,k)*J_old(:,:,s,k)];
                        X_new(:,:,s,k) == semidefinite(4);
                    end
                end

J_old(:,:,s,k) is a 2*2 semidefinite matrix, Power_old(s,k) is a positive scalar. However, this error ‘Conversion to double from cvx is not possible’ occurs when another function

[M_s(k) = -lambda_k*log2(1+Power_Allocation_Strategy(s,k)*(abs(RISphase'*B_ks*T_ks))^2/N0) + Omega_new(s,k) + v]

calls ‘Omega_new’. How can I correct it ? Thank you very much.

2

It is not clear from the description what the actual exact program flow is.

If the function is called from within your CVX program (after the variable declaration), the function should "know* (inherit) that is a CVX variable, and that expressions involving it are CVX expressions.

The error you received may occur when expression holders (arrays) are not declared or used properly. I don’t know what specifically is the reason for the error in your case. Perhaps M_s` needs to be declared as an expression holder, but isn’t?

3

Thank you Sir, I have solved the problem. I changed the version from 3.0 to 2.2, it’s OK.