[gush]

i need to calculate particle residence time in each cell and found out a code in the forum. but i cant interpret it because it gives parse error. i also checked parse error solutions mentioned here (file name, same folder issue etc.) but couldnt solve it also. i have some other UDFs as this one and they work fine.

my questions are:
1- can you please give me an idea about parse error?
2- is this code sutiable for particle residence time calculations? (if it is possbile to compile or interpret)

DEFINE_DPM_SCALAR_UPDATE(dose, c, t, initialize, p)
{

if (initialize)
{
P_USER_REAL(p,0) = 0; /* this variable will hold the cell residence time, we initialize it here */
}
else
{
P_USER_REAL(p,0) = P_TIME(p)-P_TIME0(p) ; /* store the cell residence time into the variable */
}
}