Here I got this code and error message, could you please help me to solve it?

`cvx_begin

variable E_user(n) nonnegative

variable sigma(n) nonnegative

variable Sigma(n) nonnegative

variable Omega(n) nonnegative

obj=0;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

```
sigma=zeros(1,K_num); Sigma=zeros(1,K_num); Omega=zeros(1,K_num);
% Calculate sigma
for t=1:K_num
my_hold=zeros(M*N,M*N);
for i=1:K_num
if i~=t
my_hold=my_hold+E_user(i)*G_DDMA(:,:,i)*G_DDMA(:,:,i)';
end
end
sigma(t)=trace(pinv(D(:,:,t))*U(:,:,t)*H(:,:,t)*my_hold*H(:,:,t)'*U(:,:,t)'*(pinv(D(:,:,t)))');
end
% Calculate Sigma
for t=2:K_num
my_hold=zeros(M*N,M*N);
for i=2:K_num
if i~=t
my_hold=my_hold+E_user(i)*G_DDMA(:,:,i)*G_DDMA(:,:,i)';
end
end
Sigma(t)=trace(pinv(D(:,:,1))*U(:,:,1)*H(:,:,1)*my_hold*H(:,:,1)'*U(:,:,1)'*(pinv(D(:,:,1)))');
end
my_hold=zeros(M*N,M*N);
for i=3:K_num
my_hold=my_hold+E_user(i)*G_DDMA(:,:,i)*G_DDMA(:,:,i)';
end
Sigma(1)=trace(pinv(D(:,:,2))*U(:,:,2)*H(:,:,2)*my_hold*H(:,:,2)'*U(:,:,2)'*(pinv(D(:,:,2)))');
% Calculate Omega
for i=2:K_num
Omega(i)=trace(pinv(D(:,:,1))*U(:,:,1)*H(:,:,1)*G_DDMA(:,:,i)*G_DDMA(:,:,i)'*H(:,:,1)'*U(:,:,1)'*(pinv(D(:,:,1)))');
end
Omega(1)=trace(pinv(D(:,:,2))*U(:,:,2)*H(:,:,2)*G_DDMA(:,:,1)*G_DDMA(:,:,1)'*H(:,:,2)'*U(:,:,2)'*(pinv(D(:,:,2)))');
sigma=real(sigma);
Sigma=real(Sigma);
Omega=real(Omega);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
for i=2:n
obj=obj+log(1+2*beta(i)*sqrt(E_user(1)+alpha*Sigma(1)+N0)-beta(i)^2)*(N0+alpha*sigma(i)*Omega(1))/log(2);
end
obj=obj+log(1+2*beta(1)*sqrt(E_user(2)+alpha*Sigma(2)+N0)-beta(1)^2)*(N0+alpha*sigma(1)*Omega(2))/log(2);
maximize (obj)
E_sum=0;
for i=1:n
E_sum=E_sum+E_user(i);
end
subject to
E_sum<=E_total;
cvx_end`
```

The error was ‘Unable to perform assignment because value of type ‘cvx’ is not convertible to ‘double’.’ in the line of ‘sigma(t)’