qr_solve

qr_solve(a, b)

Solve a linear system by QR decomposition.

Mirrors the C# QRDecomposition.Solve overloads (vector and matrix right-hand sides). a need not be square: an overdetermined system is solved in the least-squares sense; an underdetermined system leaves the trailing a.shape[1] - min(a.shape) unknowns at zero (matching QRDecomposition.Solve’s own truncated back-substitution, which only ever fills indices below min(m, n)).

Parameters

Name	Type	Description	Default
a	array_like	A 2D array, M x N.	required
b	array_like	A 1D array of length M, or a 2D array with M rows.	required

Returns

Name	Type	Description
	numpy.ndarray	A 1D array of length N when b is 1D, or an N x b.shape[1] array when b is 2D.

Examples

>>> from corehydropy import qr_solve
>>> a = [[1, 2, 3], [0, 1, 4], [5, 6, 0]]
>>> qr_solve(a, [1, 2, 3])
array([27., -22.,   6.])