extendr_api::prelude::modules::qr::no_pivoting::compute

Function qr_in_place

pub fn qr_in_place<E>(
    matrix: MatMut<'_, E>,
    householder_factor: MatMut<'_, E>,
    parallelism: Parallelism<'_>,
    stack: PodStack<'_>,
    params: QrComputeParams,
)
where
    E: ComplexField,
Expand description

Computes the QR decomposition of a rectangular matrix $A$, into a unitary matrix $Q$, represented as a block Householder sequence, and an upper trapezoidal matrix $R$, such that $$A = QR.$$

The Householder bases of $Q$ are stored in the strictly lower trapezoidal part of matrix with an implicit unit diagonal, and its upper triangular Householder factors are stored in householder_factor, blockwise in chunks of blocksize×blocksize.

The block size is chosen as the number of rows of householder_factor.

§Panics

  • Panics if the number of columns of the householder factor is not equal to the minimum of the number of rows and the number of columns of the input matrix.
  • Panics if the block size is zero.
  • Panics if the provided memory in stack is insufficient (see qr_in_place_req).