public double Distance(IEnumerable <Vector> x, IEnumerable <Vector> y)
{
double distanceSum = 0;
for (int i = 0; i < x.Count(); i++)
{
for (int j = i + 1; j < y.Count(); j++)
{
distanceSum += _distanceMetric.Compute(x.ElementAt(i), y.ElementAt(j));
}
}
return(distanceSum / (x.Count() * y.Count()));
}
/// <summary>Distances.</summary>
/// <param name="x">The IEnumerable<Vector> to process.</param>
/// <param name="y">The IEnumerable<Vector> to process.</param>
/// <returns>A double.</returns>
public double Distance(IEnumerable <Vector> x, IEnumerable <Vector> y)
{
double distanceSum = 0;
int xCount = x.Count();
int yCount = y.Count();
for (int i = 0; i < xCount; i++)
{
for (int j = i + 1; j < yCount; j++)
{
distanceSum += _metric.Compute(x.ElementAt(i), y.ElementAt(j));
}
}
return(distanceSum / (double)(xCount * yCount));
}
/// <summary>
/// Pairwise distance between pairs of objects
/// </summary>
/// <see cref="http://www.mathworks.cn/help/toolbox/stats/pdist.html"/>
/// <see cref="http://www.mathworks.cn/help/toolbox/stats/squareform.html"/>
/// <param name="m"></param>
/// <param name="dis">距离度量方式</param>
/// <param name="vtype"></param>
/// <returns></returns>
public static Matrix PDist(Matrix m, IDistance dis, VectorType vtype = VectorType.Column)
{
int count = vtype == VectorType.Row ? m.RowCount : m.ColumnCount;
DenseMatrix result = new DenseMatrix(count, count);
for (int i = 0; i < count; i++)
{
Vector x1 = (Vector)(vtype == VectorType.Row ? m.Row(i) : m.Column(i));
for (int j = i + 1; j < count; j++)
{
Vector x2 = (Vector)(vtype == VectorType.Row ? m.Row(j) : m.Column(j));
result[i, j] = dis.Compute(x1, x2);
result[j, i] = result[i, j];
}
}
return(result);
}
/// <summary>Distances.</summary>
/// <param name="x">The IEnumerable<Vector> to process.</param>
/// <param name="y">The IEnumerable<Vector> to process.</param>
/// <returns>A double.</returns>
public double Distance(IEnumerable <Vector> x, IEnumerable <Vector> y)
{
double leastDistance = int.MaxValue;
for (var i = 0; i < x.Count(); i++)
{
for (var j = i + 1; j < y.Count(); j++)
{
var distance = _metric.Compute(x.ElementAt(i), y.ElementAt(j));
if (distance < leastDistance)
{
leastDistance = distance;
}
}
}
return(leastDistance);
}
/// <summary>Distances.</summary>
/// <param name="x">The IEnumerable<Vector> to process.</param>
/// <param name="y">The IEnumerable<Vector> to process.</param>
/// <returns>A double.</returns>
public double Distance(IEnumerable <Vector> x, IEnumerable <Vector> y)
{
var maxDistance = double.MinValue;
for (var i = 0; i < x.Count(); i++)
{
for (var j = i + 1; j < y.Count(); j++)
{
var distance = _metric.Compute(x.ElementAt(i), y.ElementAt(j));
if (distance > maxDistance)
{
maxDistance = distance;
}
}
}
return(maxDistance);
}
public double Distance(IEnumerable <Vector> x, IEnumerable <Vector> y)
{
var length = x.ElementAt(0).Length;
Vector xs = new Vector(length);
Vector ys = new Vector(length);
// Sum up all values in x
foreach (var v in x)
{
for (int i = 0; i < v.Length; i++)
{
xs[i] += v[i];
}
}
// Sum up all values in y
foreach (var v in y)
{
for (int i = 0; i < v.Length; i++)
{
ys[i] += v[i];
}
}
// Calculate the average values
for (int i = 0; i < xs.Length; i++)
{
xs[i] = xs[i] / length;
}
// Calculate the average values
for (int i = 0; i < ys.Length; i++)
{
ys[i] = ys[i] / length;
}
return(_distanceMetric.Compute(xs, ys));
}
public double Distance(IEnumerable <Vector> x, IEnumerable <Vector> y)
{
double distance = -1;
double leastDistance = Int32.MaxValue;
for (int i = 0; i < x.Count(); i++)
{
for (int j = i + 1; j < y.Count(); j++)
{
distance = _distanceMetric.Compute(x.ElementAt(i), y.ElementAt(j));
if (distance < leastDistance)
{
leastDistance = distance;
}
}
}
return(leastDistance);
}
/// <summary>Distances.</summary>
/// <param name="x">The IEnumerable<Vector> to process.</param>
/// <param name="y">The IEnumerable<Vector> to process.</param>
/// <returns>A double.</returns>
public double Distance(IEnumerable <Vector> x, IEnumerable <Vector> y)
{
return(_metric.Compute(x.Mean(), y.Mean()));
}
