`scipy.linalg._flapack:ctpmqrt`

Signature

def ctpmqrt(l, v, t, a, b, side = L, trans = N, overwrite_a = 0, overwrite_b = 0)

Multiply a matrix by the Q of a triangular-pentagonal QR factorization (LAPACK ctpmqrt).

The matrix multiplied is the pair (a, b), the same split tpqrt uses.

l : int: Order of the trapezoidal part of v; 0 makes it rectangular.
v : ndarray: The reflectors tpqrt left in its b.
t : ndarray: Upper triangular block reflectors, shape (nb, k). Its row count is taken as the block size and its column count as the reflector count.
a : ndarray: Leading block; shape (k, n) when side is 'L' and (m, k) when 'R'.
b : ndarray: Trailing block, shape (m, n).
side : str, optional: 'L' for Q @ c, 'R' for c @ Q. Default is 'L'.
trans : str, optional: 'N' to apply Q, 'C' to apply its conjugate transpose. Default is '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 leading block of the product.
b : ndarray: The trailing block of the product.
info : int: 0 on success; if negative, the -info-th argument had an illegal value.