Hello,

My model has a multi-dimensional *variable* x(m,n,p) and another multi-dimensional *expression* f(m,n,p). However, when I initialize f and compute f as linear/affine function of x, I still got the same error from Matlab for not using expression. My code is as follows:

variable x(m,n,p);

expression f(m,n,p);

f = zeros(m,n,p);

for i=1:m

for j = 1:n

for k = 1:p

f(i,j,k) = f(i,j,k) + x(a(i),b(j),c(k))/d;

end

end

end

where a(.), b(.), c(.) are some transformation of indices and d is a constant. The Matlab error is

*The following error occurred converting from cvx to double:*

*Error using double*

*Conversion to double from cvx is not possible.*

Do you know what the problem is here?

Thanks,

Vinh