/// <summary>
/// A = A + B*s <=> A[row,col] = A[row,col] + B[row,col]*s
/// </summary>
/// <param name="A">the matrix to modify.</param>
/// <param name="B">the matrix to stay unaffected.</param>
/// <param name="s">the scalar; can have any value.</param>
/// <returns><i>A</i> (for convenience only).</returns>
public static DoubleMatrix2D PlusMult(DoubleMatrix2D A, DoubleMatrix2D B, double s)
{
return A.Assign(B, F2.PlusMult(s));
}
/// <summary>
/// A = A - B*s <=> A[i] = A[i] - B[i]*s
/// </summary>
/// <param name="A">the matrix to modify.</param>
/// <param name="B">the matrix to stay unaffected.</param>
/// <param name="s">the scalar; can have any value.</param>
/// <returns><i>A</i> (for convenience only).</returns>
public static DoubleMatrix1D MinusMult(DoubleMatrix1D A, DoubleMatrix1D B, double s)
{
return A.Assign(B, F2.MinusMult(s));
}
/// <summary>
/// Manhattan distance function; <i>Sum( abs(x[i]-y[i]) )</i>.
/// </summary>
/// <returns></returns>
public static VectorVectorFunction MANHATTAN()
{
return((a, b) => a.Aggregate(b, F2.Plus, F2.Chain(F1.Abs, F2.Minus)));
}
/// <summary>
/// Maximum distance function; <i>Max( abs(x[i]-y[i]) )</i>.
/// </summary>
/// <returns></returns>
public static VectorVectorFunction MAXIMUM()
{
return((a, b) => a.Aggregate(b, F2.Max, F2.Chain(F1.Abs, F2.Minus)));
}
/// <summary>
/// Bray-Curtis distance function; <i>Sum( abs(x[i]-y[i]) ) / Sum( x[i]+y[i] )</i>.
/// </summary>
/// <returns></returns>
public static VectorVectorFunction BRAY_CURTIS()
{
return((a, b) => a.Aggregate(b, F2.Plus, F2.Chain(F1.Abs, F2.Minus)) / a.Aggregate(b, F2.Plus, F2.Plus));
}
//private static Cern.Jet.Math.Functions.DoubleDoubleFunctions F;
/// <summary>
/// Euclidean distance function; <i>Sqrt(Sum( (x[i]-y[i])^2 ))</i>.
/// </summary>
/// <returns></returns>
public static VectorVectorFunction EUCLID()
{
return((a, b) => System.Math.Sqrt(a.Aggregate(b, F2.Plus, F2.Chain(F1.Square, F2.Minus))));
}
