Exercise

Standardizing Your Data

In the lecture, we saw that you can learn a lot about a dataset by creating the matrix \(A^TA\) from it. In this exercise, you'll do that with athletic data for players entering the National Football League college draft. The dataset combine is loaded for you.

Instructions

100 XP

Extract only the numerical elements of the data frame by taking only the 5th through 12th columns. Call this A (we cannot do math on the non-numerical components in columns 1 through 4).
Turn this data frame into a matrix by using the as.matrix() command.
Subtract the mean of each of the columns of the matrix.