User`s guide

4 Guidelines for Writing C MEX S-Functions
4-32
ssSetInputPortOverWritable(S, 0, TRUE);
if (!ssSetNumOutputPorts(S, 1)) return;
ssSetOutputPortWidth(S, 0, DYNAMICALLY_SIZED);
ssSetOutputPortTestPoint(S, 0, FALSE);
ssSetNumSampleTimes(S, 1);
ssSetSFcnParamNotTunable(S, XDATAEVENLYSPACED_PIDX);
ssSetOptions(S, SS_OPTION_EXCEPTION_FREE_CODE);
} /* mdlInitializeSizes */
/* Function: mdlInitializeSampleTimes ==========================================
* Abstract:
* The lookup inherits its sample time from the driving block.
*/
static void mdlInitializeSampleTimes(SimStruct *S)
{
ssSetSampleTime(S, 0, INHERITED_SAMPLE_TIME);
ssSetOffsetTime(S, 0, 0.0);
} /* end mdlInitializeSampleTimes */
#define MDL_START /* Change to #undef to remove function */
#if defined(MDL_START)
/* Function: mdlStart ==========================================================
* Abstract:
* Here we cache the state (true/false) of the XDATAEVENLYSPACED parameter.
* We do this primarily to illustrate how to “cache” parameter values (or
* information that is computed from parameter values) that do not change
* for the duration of the simulation (or in the generated code). In this
* case, rather than repeated calls to mxGetPr, we save the state once.
* This results in a slight increase in performance.
*/
static void mdlStart(SimStruct *S)
{
SFcnCache *cache = malloc(sizeof(SFcnCache));
if (cache == NULL) {
ssSetErrorStatus(S,”memory allocation error”);
return;
}
ssSetUserData(S, cache);
if (mxGetScalar(XDATAEVENLYSPACED(S)) != 0.0){
cache->evenlySpaced = TRUE;
}else{