Python Programming

Try practising your NumPy skills a bit more with the following set of problems!

Challenge #1

Use NumPy to solve the following equation to find $w$ given $X$ and $y$:

$w = (X^{T} X) X^{T} y$

where $X^T$ is the transpose of $X$.

You are given x and y in the code below.

import numpy as np

x = np.array([[1, 2, 3], [2, 4, 5]])
y = np.array([3, 5])
w = ?????
assert np.all(w == np.array([ 767, 1534, 2001]))

👀 Peek at sample solutions

import numpy as np

x = np.array([[1, 2, 3], [2, 4, 5]])
y = np.array([3, 5])

w = (x.T @ x) @ x.T @ y

# or use np.matmul() and np.transpose()
w = np.matmul(
        np.matmul(
            np.matmul(x.transpose(), x),
            x.transpose()
        ), 
        y
    )