[petsc-users] Store type (Eigen::Vector2d) in a petsc vec

[Jed Brown]

My suggestion is to use PETSc like usual and inside your
residual/Jacobian evaluation, for each cell or batch of cells, create
Eigen objects.  For size 2d or 3d, it won't matter much whether you make
them share memory with the PETSc Vec -- the Eigen types should mostly
exist in registers.

Andrew Parker via petsc-users <petsc-users at mcs.anl.gov> writes:

> Hi,
>
> I have quite a bit of working code that uses eigen vector2d/3d (and some
> corresponding matrix3d types) to allow for local linAlg.  I would like to
> store these within a petsc vector. So for example to have a vector for all
> cells of velocity-vectors in 2d held for each cell within an eigen
> vector2d, within a Petsc Vec for all cells.  What would be the best way to
> achieve this within petsc? I would like to make full use of petsc
> capabilities including parallel (ghost updating, partitioning etc),
> likewise those of eigen's for local linAlg on small fixed sized vectors, so
> how best to achieve this to allow for both eco-systems?
> Thanks,
> Andy