Function extendr_api::prelude::modules::lu::partial_pivoting::compute::lu_in_place
pub fn lu_in_place<'out, I, E>(
matrix: MatMut<'_, E>,
perm: &'out mut [I],
perm_inv: &'out mut [I],
parallelism: Parallelism<'_>,
stack: PodStack<'_>,
params: PartialPivLuComputeParams,
) -> (PartialPivLuInfo, PermRef<'out, I>)where
I: Index,
E: ComplexField,
Expand description
Computes the LU decomposition of the given matrix with partial pivoting, replacing the matrix with its factors in place.
The decomposition is such that: $$PA = LU,$$ where $P$ is a permutation matrix, $L$ is a unit lower triangular matrix, and $U$ is an upper triangular matrix.
$L$ is stored in the strictly lower triangular half of matrix
, with an implicit unit
diagonal, $U$ is stored in the upper triangular half of matrix
, and the permutation
representing $P$, as well as its inverse, are stored in perm
and perm_inv
respectively.
After the function returns, perm
contains the order of the rows after pivoting, i.e. the
result is the same as computing the non-pivoted LU decomposition of the matrix matrix[perm, :]
. perm_inv
contains its inverse permutation.
§Output
- The number of transpositions that constitute the permutation,
- a structure representing the permutation $P$.
§Panics
- Panics if the length of the permutation slices is not equal to the number of rows of the matrix.
- Panics if the provided memory in
stack
is insufficient (seelu_in_place_req
).