◆ qr() [1/2]

template<Rank rank>

std::tuple< Tensor< rank >, Tensor< 2 > > syten::QR::qr	(	Tensor< rank > const &	in,
		Index	uncombinedLeg,
		DecompRescaleCGC const	rescaleCGC = `DecompRescaleCGC::Yes`,
		FullQR const	full = `FullQR{false}`,
		SourceLocation const &	loc = `SourceLocation::current()`
	)

A nicer interface to QR decompositions.

Use as (e.g.)

auto [q, r] = QR::qr(in, 4);

syten::QR::qr

void qr(Tensor< rank > const &in, Index uncombinedLeg, Tensor< rank > &q, Tensor< 2 > &r, DecompRescaleCGC const rescaleCGC=DecompRescaleCGC::Yes, FullQR const full=FullQR{false}, SourceLocation location=SourceLocation::current())

QR decomposition orthogonalisation, does not truncate!

Definition: tensor_qr.h:50

q and r will hold the standard output tensors afterwards. Contracting (in the above example) the first leg of r with the fourth leg of q will result in in.