Class HierarchicalNSW

Approximate nearest-neighbor search index object based on Hierarchical navigable small world graphs.

const numDimensions = 5;
const maxElements = 1000;

index = new HierarchicalNSW('l2', numDimensions);
index.initIndex(maxElements, 16, 200, 100);

index.addPoint([0, 1, 2, 3, 4], 0);
index.addPoint([1, 2, 3, 4, 5], 1);
index.addPoint([3, 4, 5, 6, 6], 2);

const numNeighbors = 3;
const result = index.searchKnn([1, 4, 2, 3, 4], numNeighbors);

console.table(result);

Hierarchy

HierarchicalNSW

Index

Constructors

constructor

Methods

addPoint getCurrentCount getEf getIdsList getMaxElements getNumDimensions getPoint initIndex markDelete readIndex readIndexSync resizeIndex searchKnn setEf unmarkDelete writeIndex writeIndexSync

Constructors

constructor

new HierarchicalNSW(spaceName, numDimensions): HierarchicalNSW
Parameters
- spaceName: SpaceName
  
  The metric space to create for the index ('l2', 'ip', or 'cosine').
- numDimensions: number
  
  The dimesionality of metric space.
Returns HierarchicalNSW
- Defined in index.d.ts:187

Methods

addPoint

addPoint(point, label, replaceDeleted?): void
adds a datum point to the search index.
Parameters
- point: number[]
  
  The datum point to be added to the search index.
- label: number
  
  The index of the datum point to be added.
- Optional replaceDeleted: boolean
  
  The flag to replace a deleted element (default: false).
  
  Optional
Returns void
- Defined in index.d.ts:240

getCurrentCount

getCurrentCount(): number
returns the number of data points currently indexed.

Returns number
The number of data points currently indexed.
- Defined in index.d.ts:279

getEf

getEf(): number
returns the ef parameter.

Returns number
The ef parameter value.
- Defined in index.d.ts:289

getIdsList

getIdsList(): number[]
returns a list of all elements' indices.

Returns number[]
The list of indices.
- Defined in index.d.ts:263

getMaxElements

getMaxElements(): number
returns the maximum number of data points that can be indexed.

Returns number
The maximum number of data points that can be indexed.
- Defined in index.d.ts:274

getNumDimensions

getNumDimensions(): number
returns the dimensionality of data points.

Returns number
The dimensionality of data points.
- Defined in index.d.ts:284

getPoint

getPoint(label): number[]
returns the datum point vector specified by label.
Parameters
- label: number
  
  The index of the datum point.
Returns number[]
The datum point vector.
- Defined in index.d.ts:269

initIndex

initIndex(maxElements, m?, efConstruction?, randomSeed?, allowReplaceDeleted?): void
Initialize index.
Parameters
- maxElements: number
  
  The maximum number of elements.
- Optional m: number
  
  The maximum number of outgoing connections on the graph (default: 16).
  
  Optional
- Optional efConstruction: number
  
  The parameter that controls speed/accuracy trade-off during the index construction (default: 200).
  
  Optional
- Optional randomSeed: number
  
  The seed value of random number generator (default: 100).
  
  Optional
- Optional allowReplaceDeleted: boolean
  
  The flag to replace deleted element when adding new element (default: false).
  
  Optional
Returns void
- Defined in index.d.ts:196
initIndex(opts): void
Initialize index.
Parameters
- opts: {
      allowReplaceDeleted?: boolean;
      efConstruction?: number;
      m?: number;
      maxElements: number;
      randomSeed?: number;
  }
  - Optional allowReplaceDeleted?: boolean
  - Optional efConstruction?: number
  - Optional m?: number
  - maxElements: number
  - Optional randomSeed?: number
Returns void
- Defined in index.d.ts:206

markDelete

markDelete(label): void
marks the element as deleted. The marked element does not appear on the search result.
Parameters
- label: number
  
  The index of the datum point to be marked.
Returns void
- Defined in index.d.ts:245

readIndex

readIndex(filename, allowReplaceDeleted?): Promise<boolean>
loads the search index.
Parameters
- filename: string
  
  The filename to read from.
- Optional allowReplaceDeleted: boolean
  
  The flag to replace deleted element when adding new element (default: false).
  
  Optional
Returns Promise<boolean>
- Defined in index.d.ts:212

readIndexSync

readIndexSync(filename, allowReplaceDeleted?): void
loads the search index.
Parameters
- filename: string
  
  The filename to read from.
- Optional allowReplaceDeleted: boolean
  
  The flag to replace deleted element when adding new element (default: false).
  
  Optional
Returns void
- Defined in index.d.ts:218

resizeIndex

resizeIndex(newMaxElements): void
resizes the search index.
Parameters
- newMaxElements: number
  
  The new maximum number of data points.
Returns void
- Defined in index.d.ts:233

searchKnn

searchKnn(queryPoint, numNeighbors, filter?): SearchResult
returns numNeighbors closest items for a given query point.
Parameters
- queryPoint: number[]
  
  The query point vector.
- numNeighbors: number
  
  The number of nearest neighbors to search for.
- Optional filter: FilterFunction
  
  The function filters elements by its labels.
  
  Optional
Returns SearchResult
The search result object consists of distances and indices of the nearest neighbors found.
- Defined in index.d.ts:258

setEf

setEf(ef): void
sets the ef parameter.
Parameters
- ef: number
  
  The size of the dynamic list for the nearest neighbors.
Returns void
- Defined in index.d.ts:294

unmarkDelete

unmarkDelete(label): void
unmarks the element as deleted.
Parameters
- label: number
  
  The index of the datum point to be unmarked.
Returns void
- Defined in index.d.ts:250

writeIndex

writeIndex(filename): Promise<boolean>
saves the search index.
Parameters
- filename: string
  
  The filename to save to.
Returns Promise<boolean>
- Defined in index.d.ts:223

writeIndexSync

writeIndexSync(filename): void
saves the search index.
Parameters
- filename: string
  
  The filename to save to.
Returns void
- Defined in index.d.ts:228

Class HierarchicalNSW

Hierarchy

Index

Constructors

Methods

Constructors

constructor

Parameters

spaceName: SpaceName

numDimensions: number

Returns HierarchicalNSW

Methods

addPoint

Parameters

point: number[]

label: number

Optional replaceDeleted: boolean

Returns void

getCurrentCount

Returns number

getEf

Returns number

getIdsList

Returns number[]

getMaxElements

Returns number

getNumDimensions

Returns number

getPoint

Parameters

label: number

Returns number[]

initIndex

Parameters

maxElements: number

Optional m: number

Optional efConstruction: number

Optional randomSeed: number

Optional allowReplaceDeleted: boolean

Returns void

Parameters

opts: { allowReplaceDeleted?: boolean; efConstruction?: number; m?: number; maxElements: number; randomSeed?: number; }

Optional allowReplaceDeleted?: boolean

Optional efConstruction?: number

Optional m?: number

maxElements: number

Optional randomSeed?: number

Returns void

markDelete

Parameters

label: number

Returns void

readIndex

Parameters

filename: string

Optional allowReplaceDeleted: boolean

Returns Promise<boolean>

readIndexSync

Parameters

filename: string

Optional allowReplaceDeleted: boolean

Returns void

resizeIndex

Parameters

newMaxElements: number

Returns void

searchKnn

Parameters

queryPoint: number[]

numNeighbors: number

Optional filter: FilterFunction

Returns SearchResult

setEf

Parameters

ef: number

Returns void

unmarkDelete

Parameters

label: number

Returns void

`Optional` replaceDeleted: boolean

`Optional` m: number

`Optional` efConstruction: number

`Optional` randomSeed: number

`Optional` allowReplaceDeleted: boolean

opts: {
allowReplaceDeleted?: boolean;
efConstruction?: number;
m?: number;
maxElements: number;
randomSeed?: number;
}

`Optional` allowReplaceDeleted?: boolean

`Optional` efConstruction?: number

`Optional` m?: number

`Optional` randomSeed?: number

`Optional` allowReplaceDeleted: boolean

`Optional` allowReplaceDeleted: boolean

`Optional` filter: FilterFunction