Thank you very much. One last thing: with VecCreateMPIWithArray, if I
pass a NULL pointer for the array of values, then nothing is done and I
need to use VecPlaceArray/VecResetArray.
With MatCreateDense, if I pass a NULL pointer for the array of values,
then PETSc allocates the memory. Why is there such a difference? Is
there a way to create a dense matrix with no storage attached to it
(that will of course be then set via
MatDensePlaceArray/MatDenseResetArray)?
Thanks,
Pierre
On Mon, 29 May 2017 19:45:27 -0500, Barry Smith wrote:
I have added MatDensePlaceArray() and MatDenseResetArray() in
https://bitbucket.org/petsc/petsc/branch/barry/feature-matdenseplacearray
Barry
On May 29, 2017, at 3:46 PM, Pierre Jolivet
<[email protected]> wrote:
On 29 May 2017, at 22:20, Jed Brown <[email protected]> wrote:
That makes perfect sense (assuming I'm not wrong about the
MatAssemblyBegin/MatAssemblyEnd). MatSetUpMultiply_MPIDense would
still
be called at each iteration but I doubt this is too costly.
It creates a VecScatter so it isn't nothing (in terms of parallel
semantics), but I'd like to see profiling data before chasing this
around.
Sure, I'll use that and will look out for any occurrence of
"MatDensePlaceArray" (or stuff like that) in the logs, in case it is
implemented.
Thanks!
