Use of MatCreateMPIAIJ and VecCreateMPI when ghost cells are present

Wee-Beng TAY zonexo at
Mon Apr 13 22:50:47 CDT 2009


In the past, I did not use ghost cells. Hence, for e.g., on a grid 8x8, 
I can divide into 8x2 each for 4 processors i.e. divide the y direction 
because in my computation, usually y no. of cells > x no. of cells. this 
will minimize the exchange of values.

Now, with ghost cells, it has changed from x,y=1 to 8 to 0 to 9, i.e., 
the grid is now 10x10 hence to divide to 4 processors, it will not be an 
integer because 10/4 is not an interger. I'm thinking of using 6x6 grid, 
and including ghost cells becomes 8x8. Is this the right/best way?

Thank you very much and have a nice day!

Yours sincerely,

Wee-Beng Tay


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