dvector

Vector distance functions for Daft, implemented as a native extension.

Functions

Function	Description	Input	Output
l2_distance(a, b)	Euclidean distance	float vectors	Float64
inner_product(a, b)	Negative inner product (pgvector convention)	float vectors	Float64
cosine_distance(a, b)	Cosine distance (null for zero-norm)	float vectors	Float64
l1_distance(a, b)	Manhattan distance	float vectors	Float64
hamming_distance(a, b)	Count of differing positions	boolean vectors	UInt32
jaccard_distance(a, b)	1 - intersection/union (null if union is empty)	boolean vectors	Float64

Vectors can be FixedSizeList, List, or LargeList columns. Float vectors support Float32 and Float64 elements.

Install

Requires a Rust toolchain and setuptools-rust.

Usage

import daft
import dvector
from dvector import l2_distance

# Load the extension into the active session
daft.load_extension(dvector)

df = daft.from_pydict({
    "a": [[1.0, 2.0, 3.0], [0.0, 0.0, 0.0]],
    "b": [[4.0, 5.0, 6.0], [1.0, 1.0, 1.0]],
})

df.select(l2_distance(daft.col("a"), daft.col("b"))).collect()
# ╭───────────╮
# │ result    │
# │ ---       │
# │ Float64   │
# ╞═══════════╡
# │ 5.196152  │
# ├╌╌╌╌╌╌╌╌╌╌╌┤
# │ 1.732051  │
# ╰───────────╯

Development

# Build and install with the native library
uv pip install -e .

# Run tests
pytest -v tests/