scipy.linalg.lapack.dtpqrt

scipy.linalg.lapack.dtpqrt(l, nb, a, b, overwrite_a=0, overwrite_b=0) = <flapack function dtpqrt>

Blocked QR factorization of a triangular-pentagonal matrix (LAPACK dtpqrt).

The operand is the square upper triangular a stacked on the pentagonal b.

Parameters:

lint

Order of the trapezoidal part of b; 0 makes b rectangular.

nbint

Block size, at least 1 and no larger than the factorization allows.

andarray

Square upper triangular block, shape (n, n).

bndarray

Pentagonal block, shape (m, n).

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

The triangular block of the factorization.

bndarray

The reflectors, overwriting b.

tndarray

The upper triangular block reflectors.

infoint

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