Hello everyone,

I am using CVX tool on MATLAB for an optimization problem with two variables (one variable is a vector X and the other is a scalar t). However, My variables are within exponential function in the objective function.

As shown here in this example:

Here is my first code sample:

```
cvx_begin
variables t X(N)
obj=norm(A-exp(1j*X).exp(-2*j*t),2);
minimize(obj)
cvx_end
```

Then I reformulated the optimization problem as follows to adhere to the no-product rule of CVX:

```
cvx_begin
variables t X(N)
obj=norm(A-exp(1j*X-2*j*t),2);
minimize(obj)
cvx_end
```

However I sill face this error message:

Error using - (line 27)

Disciplined convex programming error:

Invalid operations:

{0.0645916+1j*-0.997912} - {log affine}

As long as the variables are within the exponential or any other function like cos and sin, the optimization doesnâ€™t run and generates an error.

Is there any way where I can include my variables within exp() in the objective?

Many thanks in advance!