Given a general matrix pair (A,B) with real entries, we provide software routines for computing a generalized Schir decomposition (S,T). The real and complex conjugate pairs of eigenvalues appears as 1 x 1 and 2 x 2 blocks respectively, along the diagonals of (S,T) and can be rendered in any order. Typically, this functionality is used to compute orthogonal bases for a pair of deflating subspaces corresponding to a selected set of eigenvalues. The package is written in Fortran 90 and targets distributed memory machines.
Page Responsible: Frank Drewes 2024-11-21