@saehrimnir/druidjs / Annoy

Class: Annoy<T>

Defined in: knn/Annoy.js:45

Annoy-style (Approximate Nearest Neighbors Oh Yeah) implementation using Random Projection Trees.

This implementation builds multiple random projection trees where each tree randomly selects two points and splits the space based on a hyperplane equidistant between them.

Key features:

• Multiple random projection trees for better recall
• Each tree uses random hyperplanes for splitting
• Priority queue search for better recall
• Combines results from all trees

Best suited for:

• High-dimensional data
• Approximate nearest neighbor search
• Large datasets
• When high recall is needed with approximate methods

Template

See

• https://github.com/spotify/annoy
• https://erikbern.com/2015/09/24/nearest-neighbors-and-vector-models-epilogue-curse-of-dimensionality.html

Extends

• KNN

Type Parameters

Type Parameter	Description
T extends number[] | Float64Array

Constructors

Constructor

new Annoy<T>(elements: T[], parameters?: ParametersAnnoy): Annoy<T>;

Defined in: knn/Annoy.js:52

Creates a new Annoy-style index with random projection trees.

Parameters

Parameter	Type	Description
elements	T[]	Elements to index
parameters?	ParametersAnnoy	Configuration parameters

Returns

Annoy<T>

Overrides

KNN.constructor

Properties

Property	Type	Inherited from	Defined in
_elements	T[]	KNN._elements	knn/KNN.js:14
_maxPointsPerLeaf	number	-	knn/Annoy.js:69
_metric	Metric	-	knn/Annoy.js:67
_numTrees	number	-	knn/Annoy.js:68
_parameters	ParametersAnnoy	KNN._parameters	knn/KNN.js:16
_randomizer	Randomizer	-	knn/Annoy.js:71
_seed	number	-	knn/Annoy.js:70
_type	"array" | "typed"	KNN._type	knn/KNN.js:18

Accessors

num_nodes

Get Signature

get num_nodes(): number;

Defined in: knn/Annoy.js:101

Get the total number of nodes in all trees.

Returns

number

---

num_trees

Get Signature

get num_trees(): number;

Defined in: knn/Annoy.js:93

Get the number of trees in the index.

Returns

number

Methods

add()

add(elements: T[]): Annoy<T>;

Defined in: knn/Annoy.js:124

Add elements to the Annoy index.

Parameters

Parameter	Type	Description
elements	T[]	-

Returns

Annoy<T>

---

search()

search(query: T, k?: number): {
  distance: number;
  element: T;
  index: number;
}[];

Defined in: knn/Annoy.js:279

Search for k approximate nearest neighbors.

Parameters

Parameter	Type	Default value	Description
query	T	undefined	-
k?	number	5	-

Returns

{ distance: number; element: T; index: number; }[]

Overrides

KNN.search

---

search_by_index()

search_by_index(i: number, k?: number): {
  distance: number;
  element: T;
  index: number;
}[];

Defined in: knn/Annoy.js:398

Parameters

Parameter	Type	Default value	Description
i	number	undefined	-
k?	number	5	-

Returns

{ distance: number; element: T; index: number; }[]

Overrides

KNN.search_by_index

---

search_index()

search_index(i: number, k?: number): {
  distance: number;
  element: T;
  index: number;
}[];

Defined in: knn/Annoy.js:410

Alias for search_by_index for backward compatibility.

Parameters

Parameter	Type	Default value	Description
i	number	undefined	Index of the query element
k?	number	5	Number of nearest neighbors to return

Returns

{ distance: number; element: T; index: number; }[]