/**
* Returns the Euclidean distance between two points. It is used to compute the similarity degree
* of these ones.
*
* @param x the first point
* @param y the second point
* @return the Euclidean distance between the points
*/
protected static double distnorm2(DoubleMatrix1D x, DoubleMatrix1D y) {
DoubleMatrix1D z = x.copy();
z.assign(y, Functions.minus);
return z.zDotProduct(z);
}
