[petsc-users] Accessing array indices in 3D

[khalid ashraf]

Thanks Barry. It works fine. Another question, I have a Periodic Boundary
condition along x and y. So I want to use the two commented out line below.
   for (j=ys; j<ys+ym; j++) {    for (i=xs; i<xs+xm; i++) {      if (i<(mx-1))      
{      Cx=u_localptr[k][j][i+1]-u_localptr[k][j][i];      }  else      { //     
Cx=u_localptr[k][j][i]-u_localptr[k][j][0];      }      if (j<(my-1))      {      
Cy=v_localptr[k][j+1][i]-v_localptr[k][j][i];      }  else      {
 //    Cy=v_localptr[k][j][i]-v_localptr[k][0][i];      } 

Is it possible to include these non-local points [k][j][0] or [k][0][i]. Or I 
have to 
include the boundary points in the grid ? The same question when forming the A 
matrix with 

PBC. How to include the non-neighbour elements within the if statement. 

Thanks.

Khalid


      
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