UDF problem: P_VEL(p)(p->state.pos)

ORC3

Hello, I need to extract the difference of particle current velocity and initial velocity: what do I need to do? I tried using a udf, and gives error: --- #include "udf.h" #include "dpm.h"

#define P_INIT_VEL(p)(p->init_state.pos) #define P_VEL(p)(p->state.pos)

{ real h; h= P_VEL(p)(p->state.pos)-P_INIT_VEL(p)(p->init_state.pos);

return h; } -- why doesn't it work? I know its silly to ask.

Melanie