com.eignex.koblas/sparse/F64SparseLu

F64SparseLu

interface F64SparseLu : Backend(source)

Sparse LU factorization as a backend half.

Inheritors

F64Context

F64SparseLinearAlgebra

F64SparseLuAdapter

Properties

supportsBasisUpdates

open val supportsBasisUpdates: Boolean(source)

Whether factorBasis answers with a factorization that updates its factors in place. When false a replacement costs a factorization, so a caller pacing its own refactorizations has nothing left to pace.

isAvailable

open val isAvailable: Boolean

Whether this backend can do work on this host. koblas's own implementations always can, so the default is true; a binding reports whether the library it calls resolved.

isPortable

open val isPortable: Boolean

Whether this is koblas's own implementation rather than a binding to a host library. The compiled-in SIMD kernels are portable however fast they are; only something calling out counts as accelerated.

name

abstract val name: String

A short backend identifier for diagnostics (e.g. "reference").

priority

open val priority: Int

Relative preference among the backends offered for one half (F64Blas, F64Decompositions, F64Kernels or a sparse counterpart). registerBackend picks the highest; the portable reference is 0.

Functions

factor

abstract fun factor(a: F64SparseMatrix, equilibrate: Boolean = false, dropTolerance: Double = NO_DROP): F64SparseFactorization(source)

Factorize the square a into something solvable. A singular matrix comes back as a factorization reporting singular rather than as an exception, with a failedAt counting elimination steps rather than naming a column: the step that fails is the one with no acceptable pivot left, so there is no column of a to attribute it to.

Parameters

the square matrix to factorize.

equilibrate

scale rows by a power of two first; the solves undo it.

dropTolerance

discard produced entries this far below the largest magnitude, giving an incomplete factorization.

factorBasis

open fun factorBasis(basis: F64SparseMatrix): F64BasisFactorization(source)

Factor a simplex basis for column replacements.

A general sparse LU backend need not support factor updates. The default refactorizes on every replacement, which every backend can do; supportsBasisUpdates tells the two apart.