public void TestCosineDistance()
{
var distribution = new Normal(0, 5);
var vectors = Enumerable.Range(0, 10).Select(i => _cpu.CreateVector(100, j => Convert.ToSingle(distribution.Sample())).AsIndexable()).ToList();
var compareTo = Enumerable.Range(0, 20).Select(i => _cpu.CreateVector(100, j => Convert.ToSingle(distribution.Sample())).AsIndexable()).ToList();
var distances = _cpu.CalculateDistances(vectors, compareTo, DistanceMetric.Cosine);
var gpuVectors = vectors.Select(v => _cuda.CreateVector(v)).ToList();
var gpuCompareTo = compareTo.Select(v => _cuda.CreateVector(v)).ToList();
var gpuDistances = _cuda.CalculateDistances(gpuVectors, gpuCompareTo, DistanceMetric.Cosine);
FloatingPointHelper.AssertEqual(distances.AsIndexable(), gpuDistances.AsIndexable());
}
/// <summary>
/// Returns the index of the closest comparison vector for each vector
/// </summary>
public IReadOnlyList <int> GetClosest()
{
using (var distance = _lap.CalculateDistances(_data, _comparison, _distanceMetric)) {
return(Enumerable.Range(0, _data.Count)
.Select(i => _GetMinimum(distance, i).Index)
.ToList());
}
}
