public IVector FindDistances(IReadOnlyList <IVector> data, DistanceMetric distance)
{
Debug.Assert(IsValid && data.All(v => v.IsValid));
if (distance == DistanceMetric.Cosine)
{
var norm = DotProduct(this);
var dataNorm = data.Select(d => d.DotProduct(d)).ToList();
var ret = new float[data.Count];
for (var i = 0; i < data.Count; i++)
{
ret[i] = Convert.ToSingle(1d - DotProduct(data[i]) / Math.Sqrt(norm * dataNorm[i]));
}
return(_cuda.CreateVector(data.Count, i => ret[i]));
}
else if (distance == DistanceMetric.Euclidean || distance == DistanceMetric.Manhattan)
{
var ret = _cuda.CalculateDistances(new[] { this }, data, distance);
return(ret.ReshapeAsVector());
}
else
{
var distanceFunc = _GetDistanceFunc(distance);
var ret = new float[data.Count];
for (var i = 0; i < data.Count; i++)
{
ret[i] = distanceFunc(data[i]);
}
return(_cuda.CreateVector(data.Count, i => ret[i]));
}
}
public IVector ColumnL2Norm()
{
Debug.Assert(IsValid);
var norm = new List <float>();
for (var i = 0; i < _columns; i++)
{
using (var col = Column(i))
norm.Add(col.L2Norm());
}
return(_cuda.CreateVector(norm.Count, x => norm[x]));
}