Machine Learning, Data Science, Dimensionality Reduction, Intuition, Linear Algebra.
between the two vectors, and hence the smaller the dot product. So the dot product is a very natural measure for covariance. A small observation will make you realize this makes perfect sense. Remember that Vx=(x1,x2,x3) and Vy=(y1,y2,y3). If the data follows a linear relationship (y=2x), then