Clojure for Data Science

Matrices

A matrix is a two-dimensional grid of numbers. The dimensions are expressed as the number of rows and columns in the matrix.

For example, A is a matrix with four rows and two columns:

In mathematical notation, a matrix will usually be assigned to a variable with an upper-case letter to distinguish it from other variables in an equation.

We can construct a matrix from our dataset using Incanter's incanter.core/to-matrix function:

(defn ex-3-16 []
  (->> (swimmer-data)
       (i/$ ["Height, cm" "Weight"])
       (i/to-matrix)))

Incanter also defines the incanter.core/matrix function that will take a sequence of scalar values or a sequence of sequences and convert ...