/// <summary>
/// law を利用した加算
/// </summary>
protected static double[] plus(Vector l, Vector r)
{
VectorChecker.SizeEquals(l, r);
double[] ret = null;
krdlab.law.func.daxpy_r(ref ret, 1, l._body, r._body);
return(ret);
}
/// <summary>
/// law を利用した減算
/// </summary>
protected static double[] sub(Vector l, Vector r)
{
VectorChecker.SizeEquals(l, r);
double[] ret = null;
// ret := -r + l
krdlab.law.func.daxpy_r(ref ret, -1, r._body, l._body);
return(ret);
}
internal static V SubEq <V>(V v1, V v2)
where V : IRandomAccessible <double>
{
VectorChecker.SizeEquals(v1, v2);
int size = v1.Size;
for (int i = 0; i < size; ++i)
{
v1[i] -= v2[i];
}
return(v1);
}
/// <summary>
/// 2つのベクトルの相関を求める．
/// </summary>
/// <param name="vx">ベクトル</param>
/// <param name="vy">ベクトル</param>
/// <returns>相関</returns>
/// <exception cref="System.ArgumentException">
/// ベクトルのサイズが一致しないときにthrowされる．
/// </exception>
public static double Correlate(IVector vx, IVector vy)
{
VectorChecker.SizeEquals(vx, vy);
double sxy = 0.0;
double avg_x = vx.Average;
double avg_y = vy.Average;
for (int i = 0; i < vx.Size; ++i)
{
sxy += ((vx[i] - avg_x) * (vy[i] - avg_y));
}
return(sxy / Math.Sqrt(vx.Scatter * vy.Scatter));
}
/// <summary>
/// law を利用した内積
/// </summary>
protected static double dot(Vector l, Vector r)
{
VectorChecker.SizeEquals(l, r);
return(krdlab.law.func.ddot(l._body, r._body));
}
