Added dictionary constructor for SparseVector

pgvector · Jun 21, 2024 · 18129ab · 18129ab
1 parent 4c190c0
commit 18129ab
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diff --git a/src/Pgvector/SparseVector.cs b/src/Pgvector/SparseVector.cs
@@ -45,6 +45,28 @@ public SparseVector(ReadOnlyMemory<float> v)
  Values = values.ToArray();
  }
 
+ public SparseVector(IDictionary<int, float> dictionary, int dimensions)
+ {
+ List<KeyValuePair<int, float>> elements = dictionary.ToList();
+ elements.Sort((a, b) => a.Key.CompareTo(b.Key));
+
+ var indices = new List<int>();
+ var values = new List<float>();
+
+ foreach (KeyValuePair<int, float> e in elements)
+ {
+ if (e.Value != 0)
+ {
+ indices.Add(e.Key);
+ values.Add(e.Value);
+ }
+ }
+
+ Dimensions = dimensions;
+ Indices = indices.ToArray();
+ Values = values.ToArray();
+ }
+
  public SparseVector(string s)
  {
  var parts = s.Split('/', 2);

diff --git a/tests/Pgvector.CSharp.Tests/SparseVectorTests.cs b/tests/Pgvector.CSharp.Tests/SparseVectorTests.cs
@@ -18,4 +18,17 @@ public void ArrayConstructor()
  var v = new SparseVector(new float[] { 1, 0, 2, 0, 3, 0 });
  Assert.Equal(new float[] { 1, 0, 2, 0, 3, 0 }, v.ToArray());
  }
+
+ [Fact]
+ public void DictionaryConstructor()
+ {
+ var dictionary = new Dictionary<int, float>();
+ dictionary.Add(2, 2);
+ dictionary.Add(4, 3);
+ dictionary.Add(0, 1);
+ dictionary.Add(3, 0);
+ var v = new SparseVector(dictionary, 6);
+ Assert.Equal(new float[] { 1, 0, 2, 0, 3, 0 }, v.ToArray());
+ Assert.Equal(new int[] { 0, 2, 4 }, v.Indices.ToArray());
+ }
 }