scipy.linalg.lapack.chetrf

scipy.linalg.lapack.chetrf(a, lower=0, lwork=max(n, 1), overwrite_a=0) = <flapack function chetrf>

Compute the blocked Bunch-Kaufman factorization of a Hermitian matrix (LAPACK chetrf).

Parameters:

andarray

Hermitian matrix of shape (n, n).

lowerint, optional

If nonzero, the lower triangle of a is referenced; otherwise the upper. Default is 0.

lworkint, optional

Size of the workspace. Default is max(n, 1). Use chetrf_lwork for the optimal value.

overwrite_aint, optional

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

Returns:

ldundarray

The block diagonal D and the multipliers of U or L, packed into the selected triangle.

ipivndarray

Pivot indices describing the interchanges and the 1x1 / 2x2 block structure, 1-based. Pass them on to sytrs/sytri/sycon unchanged.

infoint

0 on success; if negative, the -info-th argument had an illegal value; if positive, d[info-1, info-1] is exactly zero and the factor is singular.