CosineDistance Class

Definition

public static class CosineDistance

Four cosine distance functions for float[] vectors, suitable as the distance argument of SmallWorld<TItem, TDistance>. They trade universality for performance; pass one as a Func<float[], float[], float>.

Remarks

The unit-vector variants (ForUnits, SIMDForUnits) do not verify their input — passing non-unit vectors produces wrong distances silently. Normalise on the way in. If you don't know whether your vectors are unit-normalised, use SIMD. See Distance functions.

Methods

NonOptimized

public static float NonOptimized(float[] u, float[] v)

Reference implementation with no preconditions — works for any float[], including non-unit vectors. Lowest throughput. Use for correctness checks or non-unit vectors.

ForUnits

public static float ForUnits(float[] u, float[] v)

For vectors that are already unit-normalised, without SIMD overhead. Moderate throughput. Does not check the input.

SIMD

public static float SIMD(float[] u, float[] v)

SIMD-accelerated, with no preconditions. High throughput on any modern .NET runtime. The general-purpose choice when vectors may not be unit-normalised.

SIMDForUnits

public static float SIMDForUnits(float[] u, float[] v)

SIMD-accelerated, for pre-normalised unit vectors. Highest throughput — typically 1.5–3× faster than SIMD. The common case for pre-normalised embeddings. Does not check the input.

Applies to