Store a Vector as csv-File in a Mex File

Hi guys,

I have a small Problem with storing a Vector as CSV-File using a mex function. I my goal is an nice and tidy implementation. For that reason I tried the following code:

mdlStart
 FILE *PtrTextID = ssGetPWork(S,3); 
 PtrTextID = fopen("Storage.txt", "w");

mdlUpdate
 FILE *PtrTextID = ssGetPWork(S,3);
 fprintf(PtrTextID, "Test");

mdlTerminate
 FILE *PtrTextID = ssGetPWork(S,3);
 fclose(PtrTextID);

This code leads to a Matlab crash. But if I'm using 

mdlUpdate
 FILE *PtrTextID
 PtrTextID = fopen("Storage.txt", "w");
 fprintf(PtrTextID, "Test");
 fclose(PtrTextID);

the code works pretty well and do the thinks it's used to. Thats why my guess is that ssGetPWork is not the right workspace to store an FILE-Structure. But what is the right Workspace?

Thanks for your help, CN CN

Answer 1

[Kaustubha Govind]

ssGetPWork takes only one input argument, and returns a void**. Also you need to initialize the number of PWorks first. I haven't tested this out, but I think your code should look like:

mdlInitializeSizes 
 ssSetNumPWork(S, 1);

mdlStart
 ssGetPWork(S)[0] = (void *)fopen("Storage.txt", "w");

mdlUpdate
 FILE *PtrTextID = (FILE *)(ssGetPWork(S)[0]);
 fprintf(PtrTextID, "Test");

mdlTerminate
 FILE *PtrTextID = (FILE *)(ssGetPWork(S)[0]);
 fclose(PtrTextID);

Note: ssGetPWork(S)[0] can be replaced with ssGetPWorkValue(S, 0)

[Christoph]

Hi Kaustubha,

tanks for your excellent help. Your code just works perfect. As you mananged in your note I mixed up getting Values from the DWorkSpace and the PWorkSpace.

kind regards, CN