MATLAB: S-Function return types

Question

Hello,

I am trying to generate an S-Function code from a C++ source code in which I wish both input and output to be arrays.

In my C++ code the function follows:

double* function(double param1[], param2[])

{

double *varReturn = new double[sizeof(param1[])];

…

//body

…

return varReturn;

}

In the Matlab environment I enter the Output definition:

def.OutputFcnSpec = 'double y1 = TPh(double u1[], double u2[])'; then I get the

error:

error C2440: '=' : cannot convert from 'double *' to 'real_T',

logically due to "double y1" does not be an array nor a pointer declaration. However I am having a hard time in write the output definition to make it work.

Can someone please give me some help with this. I sense I am being careless at some details or I have a misunderstanding.

Thank you.

Sincerely,

Dan

Answer 1

The compiler error occurs, because in your specification:

double y1 = TPh(double u1[], double u2[])

The output 'y1' is returned by value, not a pointer which your function returns. As José-Luis Guerrero suggested, you should probably return the output via an input pointer argument, so that your specification can be:

TPh(double u1[], double u2[], double y1[])