Circle PCA in 3D
Circle
Move the points so that they are in a circular shape. How do the points appear when n = 1 and they are projected to PC1, PC2, or PC3?
What is the variance and Explained variance ratio when points are projected onto PC1, PC2, and PC3?
Switch the number of principal components to 2. Which combination of two principal components best preserves the circular shape?
Compare the distance between the principal component planes and the points. Which two principal components create a plane that is closest to the most points?
How does the explained variance ratio relate to the distance the point are from the plane?