scipy.linalg.lapack.ssbevd#

scipy.linalg.lapack.ssbevd(ab, compute_v=1, lower=0, ldab=ab.shape[0], liwork=..., overwrite_ab=0) = <flapack function ssbevd>#

Eigenvalues and eigenvectors of a symmetric band matrix, by divide and conquer (LAPACK ssbevd).

Parameters:
abndarray

The band of the symmetric/Hermitian matrix, shape (kd + 1, n): the order n and the bandwidth kd are both read off ab itself. It is consumed rather than returned.

compute_vint, optional

If nonzero, eigenvectors are computed and z is sized for them; otherwise z comes back as a 1x1 placeholder. Default is 1.

lowerint, optional

If nonzero, ab holds the lower band; otherwise the upper. Default is 0.

ldabint, optional

Leading dimension of ab. It must equal ab.shape[0]; the argument exists only because the .pyf exposed it. Default is ab.shape[0].

liworkint, optional

Integer workspace size, at least 3 + 5n with eigenvectors and 1 without.

overwrite_abint, optional

If nonzero, ab may be overwritten in place – and it is consumed either way, never returned. Unlike the rest of this module, the default is 1; pass 0 to keep your array intact.

Returns:
wndarray

Eigenvalues in ascending order, length n. Real for every flavor.

zndarray

Eigenvectors as columns, when compute_v asked for them.

infoint

0 on success; if negative, the -info-th argument had an illegal value.