github.com/weaviate/weaviate@v1.24.6/adapters/repos/db/vector/hnsw/distancer/l2.go (about)

     1  //                           _       _
     2  // __      _____  __ ___   ___  __ _| |_ ___
     3  // \ \ /\ / / _ \/ _` \ \ / / |/ _` | __/ _ \
     4  //  \ V  V /  __/ (_| |\ V /| | (_| | ||  __/
     5  //   \_/\_/ \___|\__,_| \_/ |_|\__,_|\__\___|
     6  //
     7  //  Copyright © 2016 - 2024 Weaviate B.V. All rights reserved.
     8  //
     9  //  CONTACT: hello@weaviate.io
    10  //
    11  
    12  package distancer
    13  
    14  import "github.com/pkg/errors"
    15  
    16  var l2SquaredImpl func(a, b []float32) float32 = func(a, b []float32) float32 {
    17  	var sum float32
    18  
    19  	for i := range a {
    20  		diff := a[i] - b[i]
    21  		sum += diff * diff
    22  	}
    23  
    24  	return sum
    25  }
    26  
    27  type L2Squared struct {
    28  	a []float32
    29  }
    30  
    31  func (l L2Squared) Distance(b []float32) (float32, bool, error) {
    32  	if len(l.a) != len(b) {
    33  		return 0, false, errors.Errorf("vector lengths don't match: %d vs %d",
    34  			len(l.a), len(b))
    35  	}
    36  
    37  	return l2SquaredImpl(l.a, b), true, nil
    38  }
    39  
    40  type L2SquaredProvider struct{}
    41  
    42  func NewL2SquaredProvider() L2SquaredProvider {
    43  	return L2SquaredProvider{}
    44  }
    45  
    46  func (l L2SquaredProvider) SingleDist(a, b []float32) (float32, bool, error) {
    47  	if len(a) != len(b) {
    48  		return 0, false, errors.Errorf("vector lengths don't match: %d vs %d",
    49  			len(a), len(b))
    50  	}
    51  
    52  	return l2SquaredImpl(a, b), true, nil
    53  }
    54  
    55  func (l L2SquaredProvider) Type() string {
    56  	return "l2-squared"
    57  }
    58  
    59  func (l L2SquaredProvider) New(a []float32) Distancer {
    60  	return &L2Squared{a: a}
    61  }
    62  
    63  func (l L2SquaredProvider) Step(a, b []float32) float32 {
    64  	var sum float32
    65  
    66  	for i := range a {
    67  		diff := a[i] - b[i]
    68  		sum += diff * diff
    69  	}
    70  
    71  	return sum
    72  }
    73  
    74  func (l L2SquaredProvider) Wrap(x float32) float32 {
    75  	return x
    76  }