fill for matrix multiplication
Manav Bhatia
manav at u.washington.edu
Sun Feb 18 07:08:14 CST 2007
Hi,
I am performing a matrix multiplication of two dense matrices with
both MatMatMult and MatMatMultTranspose.
What do I choose a fill factor as? According to the definition in
the documentation: fiill = expected fill as ratio of nnz(C)/(nnz(A) +
nnz(B)).
So, If I have two full matrices A and B, I will get a full matrix
as my result. Hence, the fill factor will be 0.5. However, both these
methods give an error with a fill factor less than 1.0. Also, if I
use PETSC_DFAULT as the fill argument, it agains results in an error
since its value is -2.
Kindly help me with your advice here.
Thanks
Manav
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