[JINXIE]

Originally Posted by loving_cfd

Dear vinerm,

Thanks for your reply.

I try to search the 4 neighbor cells of every cell in the domain and assign them according to the value of this cell. (cellular automaton)

So I set an array, the size of which is the same as the grids (such as x[40][20], while the mesh is 40*20), in order to record the relative position of the cells (such as x[i+1][j] is one the east of x[i][j]).

Thus, it is necessary to establish the relationship between the array and the cells. I attempt to employ cell IDs, but no macro can be found. So I partition the domain with X-coordinate and use the cell loop to record the sequence. It doesn't work properly on the first partition zone, while it works perfectly on the rest partition zones.

Part of my code is as follows (my program has to be performed on a parallel process):
#include "udf.h"
/* define the number of cells */
#define xnum 40
#define ynum 20
/* the array */
int cell[xnum+1][ynum+1];
/* initialize the cell IDs */
DEFINE_INIT(assign_array_neighbor,d)
{
#if RP_NODE
cell_t c;
Thread *t;
int x=1,y=0; /* the first row the cells in the current partition */
int partid=0; /* partition id */
int initx=0; /* to determine if it is the first row */
int counter=0; /* to count the cell id */
thread_loop_c(t,d)
{
begin_c_loop(c,t)
{
partid=C_PART(c,t);
counter=counter+1;
if(initx==0)
{x=x+partid*xnum/partnum;
initx=1;}
y=y+1;
if(y>ynum)
{y=y-ynum;x=x+1;} /* to calculate the cell position */
cell[x][y]=0; /* assign the value in the array, then the array will be employed to assign the cells in the domain */
C_UDMI(c,t,1)=counter; /* record the cell ID */
C_UDMI(c,t,2)=x; /* record x */
C_UDMI(c,t,3)=y; /* record y */
}
end_c_loop(c,t)
}
#endif
}
The result of udm3 is in the attachment. It can be discovered that the first two rows are wrongly ordered.

Hi


Could you please tell what the meaning of "partnum" and how to retrive this variable? Thank you!

I followed your idea but cannot get similar results as yours.