Learning Forum

[engineer72]

Hello there

i have problems in using fprintf in my compiled udf. i used it in a simple udf as below, but still not working:

 

[Rob]

Listing the problems will help, as will putting the source code in the post: staff are not permitted to open/download attachments. 

[engineer72]

[rachels1001]

It's hard to tell without the console errors, but as an initial guess, the DEFINE_RW_FILE command can't be used in UDFs that are executed on Windows systems, according to the Ansys documentation. 

[engineer72]

thank U for answering. there is no error at all, the solution is done but no data is written.

so how can i export a variable's magnitudes into an external file? in simple above example,  for compiled udf and using windows system?

[Rob]

If you just need a number from a point/surface use the reports and write to a file: much easier too! 

[engineer72]

i need the number calculated in udf, so i cant find it in reports.

[SK95]

fp in the function header is a pointer to a file which is already open, therefore using fopen can lead to undefined behaviour. Try to use this code:

DEFINE_RW_FILE(writer, fp)

{

   fprintf(fp, %d, kount);

}

[SK95]

If you want to print to your own file you don't need the DEFINE_RW_FILE function. You can just write your 3 lines fopen, fprintf, fclose anywhere you want (e.g. in your DEFINE_ADJUST function). But keep in mind opening and closing a file each time, takes "a lot of time" and therefore your runtime will be longer.

[engineer72]

thank U for your attention! i tried below udf, but it shows error as i want to load the udf after building that. is the problem about using compiled udf or windows system or something?

[DrAmine]

Talking about errors: share wuth us the error? I guess your forgot to define the File you want to open.

[SK95]

Sorry I forgot to mention...you have to define the variable fp first, before using it.

FILE *fp;
fp = fopen...