User`s guide

5 Troubleshooting
5-6
S-Functions Using Math Functions
Possible problem — When you create your own S-functions that include math
functions, the S-functions compile okay, but you cannot build the application.
Solution — Add the Real-Time Windows Target header to your S-function. For
example, add
#include<math.h>
#include"rtwintgt.h"
The header #include<math.h> must precede the header
#include"rtwintgt.h".