We are now in the PCA journey, station 2.

1. Statistical Introduction
   2. Transformation of Vectors in Spaces
2. Orthogonal Projection

In the beginning course of inner product, I was quite confused with the difference between inner product and dot product. After going furhter in the course, I realize that inner product is a more general form to display how two vectors work in a space while dot product is in a Euclidean space where two vectors work out as a real number (I thought dot product is a unique form in inner product).

The property of inner product includes: symmetric, positive definite, bilinear.
I'll describe what these terms mean in the coming articles.

Have a good day. Tuesday.