`scipy.linalg._flapack:ctpqrt`

Signature

def ctpqrt(l, nb, a, b, overwrite_a = 0, overwrite_b = 0)

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

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

l : int: Order of the trapezoidal part of b; 0 makes b rectangular.
nb : int: Block size, at least 1 and no larger than the factorization allows.
a : ndarray: Square upper triangular block, shape (n, n).
b : ndarray: Pentagonal block, shape (m, n).
overwrite_a : int, optional: If nonzero, a may be overwritten in place. Default is 0.
overwrite_b : int, optional: If nonzero, b may be overwritten in place. Default is 0.

a : ndarray: The triangular block of the factorization.
b : ndarray: The reflectors, overwriting b.
t : ndarray: The upper triangular block reflectors.
info : int: 0 on success; if negative, the -info-th argument had an illegal value.