fn builtin_qr(args: &[RValue], _: &[(String, RValue)]) -> Result<RValue, RError>Expand description
qr(x) — QR decomposition via nalgebra’s column-pivoted QR.
Returns a list with class “qr” containing:
$qr: the compact QR matrix (R in upper triangle)$rank: integer rank estimate$pivot: integer permutation vector (1-based)$Q: the orthogonal Q matrix (for qr.Q() access)