Re: [petsc-users] Is sparsity of Vec exploited in MatMult?

On Thu, Feb 9, 2012 at 8:09 AM, Hui Zhang <[email protected]> wrote:

Hi,

Is sparsity of Vec exploited in MatMult? I'm implementing some domain decomposition methods. The residual is non-zero or significant only at very few nodes. Does MatMult knows that most entries of the Vec are zeros? Is there a threshold to regard an value as zero?

No. Matt

Thanks, Hui

-- 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