full name: tenpy.tools.math.qr_li
- tenpy.tools.math.qr_li(A, cutoff=1e-15)[source]¶
QR decomposition with cutoff to discard nearly linear dependent columns in Q.
Perform a QR decomposition with pivoting, discard columns where
R[i,i] < cuttoff, reverse the permututation from pivoting and perform another QR decomposition to ensure that R is upper right.
numpy.ndarray) – Matrix to be decomposed as
A = Q.R
Q, R – Decomposition of A into isometry Q^d Q = 1 and upper right R with diagonal entries larger than cutoff.
- Return type