[petsc-users] Numbering in MatView

[TAY wee-beng]

Hi,

When I use MatView to output to an ASCII file, it gives:

Mat Object: 2 MPI processes
type: mpiaij
row 0: (0, 1) (1, 0) (2, 0) (3, 0) (4, 0) (5, 0) (6, 0) (7, 0)
(8, 0) (12, -1) (13, 0) (14, 0) (24, 0) (25, 0) (26, 0) (96, 0)
(97, 0) (98, 0) (192, 0) (193, 0) (194, 0)
row 1: (0, 0) (1, 13.4413) (2, 0) (3, 0) (4, -0.00187601) (5, 0)
(6, 0) (7, 0) (8, 0) (12, 0) (13, -0.000154087) (14, 0) (24, 0)
(25, 0) (26, 0) (96, 0) (97, -1.81928e-05) (98, 0) (192, 0) (193,
0) (194, 0)
row 2: (0, 0) (1, 0) (2, 1) (3, 0) (4, 0...

So how is the row numbered?

Does it uses the natural ordering or the PETSc ordering?

It seems to be the natural ordering since it doesn't change when I use
1,2 or 4 cpus, is that so?

[Barry Smith]

If the matrix came from a DMDA then it is displayed in the "natural" ordering. Otherwise it is displayed in whatever parallel ordering it is using.

Barry

Post by TAY wee-beng
Hi,
Mat Object: 2 MPI processes
type: mpiaij
row 0: (0, 1) (1, 0) (2, 0) (3, 0) (4, 0) (5, 0) (6, 0) (7, 0) (8, 0) (12, -1) (13, 0) (14, 0) (24, 0) (25, 0) (26, 0) (96, 0) (97, 0) (98, 0) (192, 0) (193, 0) (194, 0)
row 1: (0, 0) (1, 13.4413) (2, 0) (3, 0) (4, -0.00187601) (5, 0) (6, 0) (7, 0) (8, 0) (12, 0) (13, -0.000154087) (14, 0) (24, 0) (25, 0) (26, 0) (96, 0) (97, -1.81928e-05) (98, 0) (192, 0) (193, 0) (194, 0)
row 2: (0, 0) (1, 0) (2, 1) (3, 0) (4, 0...
So how is the row numbered?
Does it uses the natural ordering or the PETSc ordering?
It seems to be the natural ordering since it doesn't change when I use 1,2 or 4 cpus, is that so?
--
Thank you
Yours sincerely,
TAY wee-beng