[petsc-users] explicit symmetric matrices

[Matthew Knepley]

On Thu, May 17, 2012 at 6:36 PM, Andrew Spott <andrew.spott at gmail.com>wrote:

> Is there a way to explicitly say that a sparse matrix is symmetric or
> hermitian and only save/load half of it?


PETSc distinguishes two kinds of information. Information about the
operator (I am symmetric) can be set with
options. This can be queried by other code in order to optimize algorithms.
It can also be checked by functions
like MatIsSymmetric().

Information about an implementation is in the type, like MATSBAIJ which
says I only store half my values. There
is no need for a symmetric matrix to be stored this way, but you can choose
this if you want.

   Matt


>
> -Andrew

-- 
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
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