Andrew Cramer <[email protected]> writes: > I get *significantly *different results from backslash and petsc using > the *same > matrix*. > > Deflection |Au-b|/|b| > Euler-Bernoulli: 4000 > Petsc: 4386 0.3 > Matlab: 4013 1.6e-10 > > I'm exporting to 6 significant figures. Condition number is rather poor > (~2e7) but I get similar or worse results with problems having lower > conditions numbers (~1e3).
Are you sure the matrices are the same? Use "-ksp_view_mat binary",
then in MATLAB, A = PetscBinaryRead('binaryoutput') if you want to get
both matrices in the same environment. Or explicitly compute the norms
in PETSc.
To debug, start with the simplest and most well-conditioned problem
that exhibits the issue.
pgpf3rYBGTG9r.pgp
Description: PGP signature
