[petsc-dev] strangness in Chebyshev estimate of eigenvalues

[Jed Brown]

Mark Adams <mfadams at lbl.gov> writes:

> My hash function is:
>
>             PetscScalar v = ((PetscScalar)((PETSC_HASH_FACT*idx)%100) -
> 49.5)/50.0;
>             ierr = VecSetValues(bb, 1, &idx, &v,
> INSERT_VALUES);CHKERRQ(ierr);
>
>
> include/petscctable.h:#define PETSC_HASH_FACT 79943

Still grid-aligned stripes on a 100xN grid.  Please stop it with these
bullshit ad-hoc hash functions.  Either use a decent hash function or
drand48.
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