README
¶
hnswgo 
A Go wrapper for hnswlib⚡
Installation
go get github.com/Eigen-DB/hnswgo/v2
Usage
package examples
import (
"fmt"
"time"
"github.com/Eigen-DB/hnswgo/v2"
)
func main() {
dimensions := 2
maxElements := 10000
m := 32
efConstruction := 400
spaceType := "l2"
seed := int(time.Now().Unix())
// instantiate the index
index, err := hnswgo.New(
dimensions,
m,
efConstruction,
seed,
uint32(maxElements),
spaceType,
)
if err != nil {
fmt.Printf("Error: %s\n", err.Error())
}
defer index.Free() // defer freeing the index from memory (don't forget in order ot prevent memory leaks)
// sample vectors
vectors := [][]float32{
{1.2, 3.4},
{2.1, 4.5},
{0.5, 1.7},
{3.3, 2.2},
{4.8, 5.6},
{7.1, 8.2},
{9.0, 0.4},
{6.3, 3.5},
{2.9, 7.8},
{5.0, 1.1},
}
// insert sample vectors
for i, v := range vectors {
err = index.InsertVector(v, uint64(i))
if err != nil {
fmt.Printf("Error: %s\n", err.Error())
}
}
k := 5
nnLabels, nnDists, err := index.SearchKNN(vectors[0], k) // perform similarity search where the first of our sample vectors is the query vector
if err != nil {
fmt.Printf("Error: %s\n", err.Error())
}
fmt.Printf("%d-nearest neighbors:\n", k)
for i := range nnLabels {
fmt.Printf("vector %d is %f units from query vector\n", nnLabels[i], nnDists[i])
}
}
Visualize the vectors in this example here.
References
Yu. A. Malkov, D. A. Yashunin. "Efficient and robust approximate nearest neighbor search using Hierarchical Navigable Small World graphs" TPAMI, preprint: [https://arxiv.org/abs/1603.09320]
Documentation
¶
Index ¶
- func Normalize(vector []float32)
- type Index
- func (i *Index) DeleteVector(label uint64) error
- func (i *Index) Free()
- func (i *Index) GetVector(label uint64) ([]float32, error)
- func (i *Index) InsertVector(vector []float32, label uint64) error
- func (i *Index) ReplaceVector(label uint64, newVector []float32) error
- func (i *Index) SaveToDisk(location string) error
- func (i *Index) SearchKNN(vector []float32, k int) ([]uint64, []float32, error)
- func (i *Index) SetEfConstruction(efConstruction int) error
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
Types ¶
type Index ¶
type Index struct {
// contains filtered or unexported fields
}
func LoadIndex ¶ added in v2.1.0
Loads a saved index and returns a reference to it.
- location: the file path of the saved index
- dim: dimension of the vector space
- spaceType: similarity metric to use in the index ("ip", "cosine", "l2". default: "l2")
- maxElements: index's vector storage capacity
Returns an instance of the saved HNSW index, or an error if there was a problem.
func New ¶
func New(dim int, m int, efConstruction int, randSeed int, maxElements uint32, spaceType string) (*Index, error)
Returns a reference to an instance of an HNSW index.
- dim: dimension of the vector space
- maxElements: index's vector storage capacity
- m: `m` parameter in the HNSW algorithm
- efConstruction: `efConstruction` parameter in the HNSW algorithm
- randSeed: random seed
- spaceType: similarity metric to use in the index ("ip", "cosine", "l2". default: "l2")
Returns an instance of an HNSW index, or an error if there was a problem initializing the index.
func (*Index) DeleteVector ¶
Marks a vector with the specified label as deleted, which omits it from KNN search.
- label: the vector's label
Returns an error if one occured.
func (*Index) GetVector ¶
Returns a vector's components using its label
- label: the vector's label
Returns the vector's components with specified label
func (*Index) InsertVector ¶
Adds a vector to the HNSW index. If the a vector with the same label already exists, the function returns an error
- vector: the vector to add to the index
- label: the vector's label
Returns an error if one occured.
func (*Index) ReplaceVector ¶ added in v2.2.0
Replaces an existing vector in the HNSW index.
- label: the vector's label
- newVector: the new vector used to replace the old vector
Returns an error if one occured.
func (*Index) SaveToDisk ¶ added in v2.1.0
Saves the index to the disk.
- location: the file path in which to save the index
Returns an error if there was a problem.
func (*Index) SearchKNN ¶
Performs similarity search on the HNSW index.
- vector: the query vector
- k: the k value
Returns the labels and distances of each of the nearest neighbors, and an error if one occured. Note: the size of both arrays can be < k if k > num of vectors in the index
func (*Index) SetEfConstruction ¶
Set's the efConstruction parameter in the HNSW index.
- efConstruction: the new efConstruction parameter
Returns an error if one occured.
Source Files
Directories