New to writing UDF
 

Hi I am writing a UDF to intialize the particle velocity of particle injection in my DPM model. I have looked up macros but not able to get the right UDF. When I interpret the UDF into the prgrm the compiler says :

Error: C:\---\prtcl_init_condn.c: line 14: structure reference not implemented

Can anyone tell me what this means!!! Also what is the basic structure of UDF to define its velocity? I have seen an example in manual but the example is of "surface reaction" and I could not understand it to apply to my cxase.

Thank you

Sandilya Garimella