Select default sparse direct solver to be used.

useUmfpack : bool, optional

Use UMFPACK over SuperLU. Has effect only if scikits.umfpack is installed. Default: True

assumeSortedIndices : bool, optional

Allow UMFPACK to skip the step of sorting indices for a CSR/CSC matrix. Has effect only if useUmfpack is True and scikits.umfpack is installed. Default: False


The default sparse solver is umfpack when available (scikits.umfpack is installed). This can be changed by passing useUmfpack = False, which then causes the always present SuperLU based solver to be used.

Umfpack requires a CSR/CSC matrix to have sorted column/row indices. If sure that the matrix fulfills this, pass assumeSortedIndices=True to gain some speed.