Euclidean Distance
The Euclidean distance Is the distance between two points in a cartesian coordinate system that is "measured by a ruler". The Euclidean distance between the points X=[x1,x2,...xn] and Y=[y1,y2,...yn] is defined as
$ dist(X,Y)=\sqrt{\sum_{i=1}^n{(x_i-y_i)^2}} $.
