[petsc-users] changing DAs matrix and coefficients ordering

[ilyas yilmaz]

Hi,

As far as I understand, DAs create matrix structure which is based on
natural ordering of mesh, ie.,

    (i,j)
cell(0,0) --> 0th row of DA matrix
cell(1,0) --> 1st row of DA matrix
cell(2,0) --> 2nd row of DA matrix and so on

and for coefficients  : (i,j-1) (i-1,j) (i,j) (i+1,j) (i,j+1)

My question is :
----------------
I need such a matrix stucture for my application that

    (i,j)
cell(0,0) --> 0th row of DA matrix
cell(0,1) --> 1st row of DA matrix
cell(0,2) --> 2nd row of DA matrix and so on

and for coefficients  : (i-1,j) (i,j-1) (i,j) (i,j+1) (i+1,j)

How can I tell this DAs?

Note:
To simplify and to stay away from processor ordering issue,
I assume that I am running DAs code on 1 cpu.


Thank you for providing PETSc library and for your help.

Regards,
Ilyas