rq_li¶
full name: tenpy.tools.math.rq_li
parent module:
tenpy.tools.math
type: function
-
tenpy.tools.math.
rq_li
(A, cutoff=1e-15)[source]¶ RQ decomposition with cutoff to discard nearly linear dependent columns in Q.
Uses
qr_li()
on tranpose of A. Note that R is nonzero in the lowest left corner; R has entries below the diagonal for non-square R.- Parameters
- A
numpy.ndarray
Matrix to be decomposed as
A = Q.R
- A
- Returns
- R, Q
numpy.ndarray
Decomposition of A into isometry Q Q^d = 1 and upper right R with diagonal entries larger than cutoff. If
M, N = A.shape
, thenR.shape = M, K
andQ.shape = K, N
withK <= min(M, N)
.
- R, Q