`scipy.linalg._flapack:dgges`

Summary

Compute the generalized Schur factorization of a matrix pair (LAPACK dgges).

dselect : callable: Generalized-eigenvalue selector, called as dselect(alphar, alphai, beta). Used only when sort_t is nonzero.
a : ndarray: Square matrix of shape (n, n).
b : ndarray: Square matrix of shape (n, n), the second member of the pair.
jobvsl : int, optional: If nonzero, the left Schur vectors are computed. Default is 1.
jobvsr : int, optional: If nonzero, the right Schur vectors are computed. Default is 1.
sort_t : int, optional: If nonzero, eigenvalues are sorted using the selector. Default is 0.
ldvsl : int, optional: Leading dimension of vsl. Default is n when jobvsl is nonzero, else 1.
ldvsr : int, optional: Leading dimension of vsr. Default is n when jobvsr is nonzero, else 1.
lwork : int, optional: Size of the workspace. Default is 8 * n + 16. Use the value reported in work[0] for the optimal value.
dselect_extra_args : tuple, optional: Extra positional arguments appended to every selector call. Default is ().
overwrite_a : int, optional: If nonzero, a may be overwritten in place. Default is 0.
overwrite_b : int, optional: If nonzero, b may be overwritten in place. Default is 0.

a : ndarray: Generalized Schur form of a.
b : ndarray: Generalized Schur form of b.
sdim : int: Number of eigenvalues the selector accepted; 0 when sort_t is 0.
alphar : ndarray: Real parts of the numerators of alpha / beta.
alphai : ndarray: Imaginary parts of the numerators of alpha / beta.
beta : ndarray: Denominators of the generalized eigenvalues.
vsl : ndarray: Left Schur vectors, or a placeholder when jobvsl is 0.
vsr : ndarray: Right Schur vectors, or a placeholder when jobvsr is 0.
work : ndarray: Workspace actually used; work[0] is the optimal lwork.
info : int: 0 on success; if negative, the -info-th argument had an illegal value; if positive, the QZ algorithm failed or the selected block could not be reordered.