about the macro P_USER_REAL(p,i)
 

I have written one udf programe about DPM,but when I hook them,it is giving me a error:P_USER_REAL(p,0): undeclared variable.Please help me!

my programe:

#include "udf.h"
#include "models.h"
#include "dpm.h"
#include "surf.h"
#include "threads.h"
#include "math.h"
#include "mem.h"
DEFINE_DPM_SCALAR_UPDATE(particle_depostion,c,t,in itialize,p)
{
int i = 0;
face_t f;
Thread *th;
real A[ND_ND];
real area=0,vol=0;
int wall_ID=4;
if (initialize)
P_USER_REAL(p, 0) = 0;
c_face_loop(c,t,i)
{
if(THREAD_ID(C_FACE_THREAD(c,t,i)) == wall_ID)
{

f=C_FACE(c,t,i);
th=C_FACE_THREAD(c,t,i);
F_AREA(A,f, th);
area = NV_MAG(A);
vol=C_VOLUME(c,t);

if(P_DIAM(p)<0.01)
{

C_UDMI(c, t, 0) +=P_DIAM(p);
P_USER_REAL(p,0) = 1.; /* "Evaporate" */

}

}
}

}

DEFINE_DPM_LAW(stop_dpm_law,p,if_cpld)
{
if (0. < P_USER_REAL(p,0))
P_MASS(p) = 0.; /* "Evaporate" */
}
DEFINE_INIT(my_init_func,d)
{
cell_t c;
Thread *t;

thread_loop_c(t,d)
{

begin_c_loop_all(c,t)
{
C_UDMI(c,t,0)=0;

}
end_c_loop_all(c,t)
}
}

Try to access the user memory of the particle in this way:

Do´t forget to enable as many user variables as you need (in your case it would be only one so far) in the UDF panel of the discrete phase model menu!

thank you
 

I have understood your mean.Tnanks.

I am using macros DEFINE_DPM_SCALAR_UPDATE. Can any one tell the means of P_USER_REAL(p,0) = P_USER_REAL(p,0) + 1.
P_USER_REAL(p,1) = 1.;
::::::::::::
some part of my UDF is
if (P_POS(p)[2]<0.03) //particle pos in z direction less then 3 cm
{
P_USER_REAL(p,1) = 0.;
}

if (P_POS(p)[2]>0.9 && P_USER_REAL(p,1) == 0.) //particle pos in z direction greater then 90 cm
{

P_USER_REAL(p,0) = P_USER_REAL(p,0) + 1.
P_USER_REAL(p,1) = 1.;
etc

Dear friend
can you tell the means of P_USER_REAL(p,0) = P_USER_REAL(p,0) + 1.
P_USER_REAL(p,1) = 1. in the macros DEFINE_DPM_SCALAR_UPDATE.

P_USER_REAL(p,i) is used for storing real data type values for each particle, where i is an integer for identifying each array.

Your first example increments the array of the current particle by one:

The second example sets the second array to one:

I've noticed these snippets are from my code in this thread and I've explained these macros here.