How do I pass a Complex input to a MATLAB file S-function?

I have an MATLAB file S-function and I want it to handle complex inputs.

Answer 1

[MathWorks Support Team]

MATLAB file S-functions cannot handle complex inputs, unlike C-Mex S-functions. However, the following workaround can be used to have MATLAB file S-functions work with complex inputs.

1. Use the Complex to Real-Imaginary block from the Simulink Math library to split the complex signal into two parts.

2. Use a Mux block from the Signals & Systems library to combine these two parts into a two element vector.

3. Pass this vector as input to the MATLAB file S function.

4. Make sure inside the MATLAB file S function the number of inputs is set to 2

sizes.NumInputs = 2;

An example that demonstrates how complex input can be handled is attached at the bottom of the page.

In the example, the conjugate of a complex number is calculated using a MATLAB file S-function.