[petsc-users] Changing a few entries in a matrix

[Matthew Knepley]

On Fri, May 8, 2015 at 4:04 PM, Ganesh Vijayakumar <ganesh.iitm at gmail.com>
wrote:

> Hello,
>
>   I have a CFD application where some entries of the matrix change every
> time step. However, the total number of non-zero elements never changes. Is
> there anyway I can efficiently do this. My current attempts at doing this
> results in running over the total initial memory allocation very soon.
>

If you know where the next elements will be, you can overallocate and fill
those entries with zeros. If not,
then we do not have a good dynamics data structure. This could be done with
hash tables I think, but we
have not had a call for it.

  Thanks,

    Matt



> ganesh
>



-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener
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