com.eignex.koblas/sparse/F64SparseKernels

F64SparseKernels

interface F64SparseKernels : Backend(source)

Sparse vector-vector routines as a backend half.

Inheritors

Properties

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

asum

abstract fun asum(x: F64SparseVector): Double(source)

Sum |x_i| over the stored entries.

axpy

abstract fun axpy(y: DoubleArray, alpha: Double, x: F64SparseVector)(source)

y += alpha·x for a sparse x into a dense y (Sparse BLAS usaxpy), touching only x's stored positions.

dot

abstract fun dot(x: F64SparseVector, y: DoubleArray): Double(source)

xᵀ·y for a sparse x against a dense y (Sparse BLAS usdot); walks only the stored entries.

abstract fun dot(x: F64SparseVector, y: F64SparseVector): Double(source)

xᵀ·y for two sparse vectors, merging their index lists in one pass. Relies on both operands being strictly ascending, which F64SparseVector validates.

nrm2

abstract fun nrm2(x: F64SparseVector): Double(source)

Euclidean norm over the stored entries, rescaled as the dense euclideanNorm is.

scatter

abstract fun scatter(x: F64SparseVector, out: DoubleArray)(source)

Write x's stored entries into out at their positions, leaving the rest of out alone (Sparse BLAS ussc). Zero-fill out first for a plain densification.