scipy.linalg.lapack.dgges

scipy.linalg.lapack.dgges(dselect, a, b, jobvsl=1, jobvsr=1, sort_t=0, ldvsl=n, ldvsr=n, lwork=8 * n + 16, dselect_extra_args=(), overwrite_a=0, overwrite_b=0) = <flapack function dgges>

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

Parameters:

dselectcallable

Generalized-eigenvalue selector, called as dselect(alphar, alphai, beta). Used only when sort_t is nonzero.

andarray

Square matrix of shape (n, n).

bndarray

Square matrix of shape (n, n), the second member of the pair.

jobvslint, optional

If nonzero, the left Schur vectors are computed. Default is 1.

jobvsrint, optional

If nonzero, the right Schur vectors are computed. Default is 1.

sort_tint, optional

If nonzero, eigenvalues are sorted using the selector. Default is 0.

ldvslint, optional

Leading dimension of vsl. Default is n when jobvsl is nonzero, else 1.

ldvsrint, optional

Leading dimension of vsr. Default is n when jobvsr is nonzero, else 1.

lworkint, optional

Size of the workspace. Default is 8 * n + 16. Use the value reported in work[0] for the optimal value.

dselect_extra_argstuple, optional

Extra positional arguments appended to every selector call. Default is ().

overwrite_aint, optional

If nonzero, a may be overwritten in place. Default is 0.

overwrite_bint, optional

If nonzero, b may be overwritten in place. Default is 0.

Returns:

andarray

Generalized Schur form of a.

bndarray

Generalized Schur form of b.

sdimint

Number of eigenvalues the selector accepted; 0 when sort_t is 0.

alpharndarray

Real parts of the numerators of alpha / beta.

alphaindarray

Imaginary parts of the numerators of alpha / beta.

betandarray

Denominators of the generalized eigenvalues.

vslndarray

Left Schur vectors, or a placeholder when jobvsl is 0.

vsrndarray

Right Schur vectors, or a placeholder when jobvsr is 0.

workndarray

Workspace actually used; work[0] is the optimal lwork.

infoint

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.