Unitary-triangular factorizations

Unitary-triangular factorizations are various decompositions of a matrix A into a product of a triangular matrix and a unitary one (or an orthogonal matrix, for a real A).

Of all these factorizations, the QR decomposition is the most known one. Other variants (such as the LQ decomposition, QL decomposition, etc.) can be reduced to the QR decomposition.