how write UDF
 

In wall BC of attachments, I want to set specified value equal to zero in uds0 in local wall location, and that set specified flux equal to zero in uds0 in other wall location, how write udf?

hello,everyone.
is there anyone who do DC nontransfer plasma modelling?
i want to ask some questions about the anode spot .
thank you very much for your attention! best wishes for everyone!

DEFINE_PROFILE(anode_spot,thread,position)
{
real NV_VEC(n);
real x;
real y;
real z;
face_t f;
Thread *t0=NULL;
begin_f_loop(f,thread)
{
F_CENTROID(n,f,thread);
x=n[0];
y=n[1];
z=n[2];
if(((x-0.004)*(x-0.004)*(x-0.004)+y*y*y+(z-0.008)*(z-0.008)*(z-0.008))<0.0025*0.0025*0.0025)
F_PROFILE(f,thread,position)=0;
else
cell_t c0=F_C0(f,thread);
t0=THREAD_T0(thread);
F_PROFILE(f,thread,position)=C_UDSI(c0,t0,V);
}
end_f_loop(f,thread)
}

please help me check right or wrong, thanks a lot.

urgent --help me
 

Please everyone help me，urgent.

I will wait for your help online，thanks.