[petsc-users] MatSetValues: reorder the values

[Hui Zhang]

On May 27, 2012, at 8:58 PM, Mohammad Mirzadeh wrote:

> > Of course, this new function sounds unnecessary because reordering v is equivalent to reordering 
> > idxm[] and idxn[].  But the second method seems not an easy task to me, is it?
> 
> 
> 
> Why not use a single AO object to hold the mapping between PETSc mapping and your maping?

Yes, thanks! I'm doing so.

> Seems to me that the indecies used in v[] are completely arbitrary; they should always go in [0,1,...,m*n], don't they?

No, I only take some non-contiguous entries of v[] to the mat. So, I need to first take out
those values to a new array, what I worried about the cost. But as Barry Smith told us, 
the cost is small.



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