scipy.linalg.lapack.chetrd#

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

Reduce a Hermitian matrix to real symmetric tridiagonal form by a unitary similarity transformation (LAPACK chetrd).

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 chetrd_lwork for the optimal value.

overwrite_aint, optional

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

Returns:
cndarray

The tridiagonal form together with the elementary reflectors that produced it, packed into a.

dndarray

Diagonal of the tridiagonal form, length n. Real for every flavor.

endarray

Off-diagonal, length n - 1. Real for every flavor.

taundarray

Scalar factors of the elementary reflectors that define Q.

infoint

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