scipy.linalg.lapack.dtgexc#
- scipy.linalg.lapack.dtgexc(a, b, q, z, ifst, ilst, wantq=1, wantz=1, lwork=4 * n + 16, overwrite_a=0, overwrite_b=0, overwrite_q=0, overwrite_z=0) = <flapack function dtgexc>#
Reorder a generalized Schur decomposition by moving one diagonal block (LAPACK
dtgexc).- Parameters:
- andarray
Upper (quasi-)triangular factor of the pencil, shape
(n, n).- bndarray
Upper triangular factor of the pencil, shape
(n, n).- qndarray
Left Schur vectors; updated when wantq is nonzero.
- zndarray
Right Schur vectors; updated when wantz is nonzero.
- ifstint
Current position of the diagonal block to move, 1-based.
- ilstint
Position to move it to, 1-based. LAPACK adjusts both when a block turns out to be 2x2; the adjusted values are not returned.
- wantqint, optional
If nonzero, the left transformation is accumulated into q. Default is 1.
- wantzint, optional
If nonzero, the right transformation is accumulated into z. Default is 1.
- lworkint, optional
Workspace size, at least
4 * n + 16; -1 requests the query. Default is4 * n + 16. The complex flavors need no workspace and take no lwork.- 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.
- overwrite_qint, optional
If nonzero, q may be overwritten in place. Default is 0.
- overwrite_zint, optional
If nonzero, z may be overwritten in place. Default is 0.
- Returns:
- andarray
The reordered first factor.
- bndarray
The reordered second factor.
- qndarray
The updated left Schur vectors.
- zndarray
The updated right Schur vectors.
- workndarray
Workspace;
work[0]holds the optimal lwork. The complex flavors do not return it.- infoint
0 on success; if negative, the
-info-th argument had an illegal value.