Mojo struct

HouseholderQR

@memory_only
struct HouseholderQR

Fields

• m_qr (Mat)
• m_hCoeffs (Vec)
• m_rows (Int)
• m_cols (Int)

Implemented traits

AnyType, Deinitable, Movable

Methods

__init__

fn def __init__(out self)

Args:

• self (Self)

Returns:

Self

compute

fn def compute(mut self, A: Mat)

Args:

• self (Self)
• A (Mat)

matrixR

fn def matrixR(self) -> Mat

The cols x cols (== m_cols x m_cols) upper-triangular R factor, as a fresh dense copy — matches Eigen's qrDecomp.matrixQR().topRows(diagSize).triangularView<StrictlyLower>().setZero().

Args:

• self (Self)

Returns:

Mat

apply_q_on_left

fn def apply_q_on_left(self, mut M: Mat)

M <- Q * M, i.e. H_0 * H_1 * ... * H_{m_cols-1} * M, applied via compact-WY panels of block_size reflectors at a time (2 GEMMs per panel) instead of one rank-1 update per reflector. M here is the full rows x rows (or cols x cols) matrixU/matrixV, so this is the single most expensive Householder-apply in the whole solve for rectangular inputs.

Args:

• self (Self)
• M (Mat)