(Tensor) the input matrix
This is a low-level function for calling LAPACK directly. This function
returns a namedtuple (a, tau) as defined in
LAPACK documentation for geqrf_ .
You'll generally want to use
Computes a QR decomposition of
input, but without constructing
\(Q\) and \(R\) as explicit separate matrices.
Rather, this directly calls the underlying LAPACK function
which produces a sequence of 'elementary reflectors'.
LAPACK documentation for geqrf_ for further details.