[petsc-users] PetscTableCreateHashSize

[Satish Balay]

On Mon, 9 Jan 2017, Jed Brown wrote:

> Satish Balay <balay at mcs.anl.gov> writes:
> > Sure - I'm using a crappy algorithm [look-up table] to get
> > "prime_number_close_to(1.4*sz)" - as I don't know how to generate
> > these numbers automatically.
> 
> FWIW, it only needs to be coprime with PETSC_HASH_FACT.

Not sure I understand - are you saying coprime requirement is easier
satisfy than a single prime?

I had switched this code to use double-hasing algorithm - and the
requirement here is - the table size be a prime number. [so I'm
attempting to estimate a prime number suitable for the table size]

I pushed the following
https://bitbucket.org/petsc/petsc/commits/d742c75fd0d514f7fa1873d5b10984bc3f363031

Satish