[SciPy-dev] new sparsetools + umfpack

Nils Wagner nwagner at iam.uni-stuttgart.de
Wed Jan 10 06:46:33 CST 2007

Robert Cimrman wrote:
> New sparsetools implementation does not require CSR/CSC column/row
> indices to be sorted in ascending order, while UMFPACK does. Currently,
> every call to umfpack module (e.g. via linsolve.solve) implicitly calls
> ensure_sorted_indices(inplace=True) method of CSR/CSC matrix, which is
> rather fast, but in many cases is not necessary and the overhead can
> become significant when solving lots of linear systems (e.g.
> FE-discretized evolutionary nonlinear PDEs) - in this case, only one
> call to ensure_sorted_indices() is necessary, then only values change,
> not the structure.
> Therefore, if there are no objections, I would like to remove the
> implicit call to ensure_sorted_indices() from umfpack and require user
> to call it explicitly (only if necessary) - an exception will be raised
> by umfpack if the matrix is not in correct form, so it cannot lead to
> hidden bugs. I will document this in linsolve, of course.
> r.
> _______________________________________________
> Scipy-dev mailing list
> Scipy-dev at scipy.org
> http://projects.scipy.org/mailman/listinfo/scipy-dev
Just curious. Is the umfpack directory in the sandbox obsolete ?


More information about the Scipy-dev mailing list