chroma-core/chroma · error · Exception

Unknown distance function: {space}

Error message

Unknown distance function: {space}

What it means

Error "Unknown distance function: {space}" thrown in chroma-core/chroma.

Source

Thrown at chromadb/segment/impl/vector/brute_force_index.py:40

    id_to_index: Dict[str, int]
    index_to_id: Dict[int, str]
    id_to_seq_id: Dict[str, int]
    deleted_ids: Set[str]
    free_indices: List[int]
    size: int
    dimensionality: int
    distance_fn: Callable[[npt.NDArray[Any], npt.NDArray[Any]], float]
    vectors: npt.NDArray[Any]

    def __init__(self, size: int, dimensionality: int, space: str = "l2"):
        if space == "l2":
            self.distance_fn = distance_functions.l2
        elif space == "ip":
            self.distance_fn = distance_functions.ip
        elif space == "cosine":
            self.distance_fn = distance_functions.cosine
        else:
            raise Exception(f"Unknown distance function: {space}")

        self.id_to_index = {}
        self.index_to_id = {}
        self.id_to_seq_id = {}
        self.deleted_ids = set()
        self.free_indices = list(range(size))
        self.size = size
        self.dimensionality = dimensionality
        self.vectors = np.zeros((size, dimensionality))

    def __len__(self) -> int:
        return len(self.id_to_index)

    def clear(self) -> None:
        self.id_to_index = {}
        self.index_to_id = {}
        self.id_to_seq_id = {}
        self.deleted_ids.clear()

View on GitHub (pinned to aecdd12c8a)

When it happens

Trigger: Thrown at chromadb/segment/impl/vector/brute_force_index.py:40 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of chroma-core/chroma@aecdd12c8a (2026-08-16). Data as JSON: /api/errors/3916c272d736fc75. Report an issue: GitHub.