An interactive field guide / Math for ML

Build intuition.
Then do the math.

See a vector stretch. Watch a surface change. Connect the mathematics to the ideas behind machine learning.

Start with the foundations ↗

For first-year college students. Start with curiosity.

Experiment 01 / Scalar multiplicationℝ²
A vector scaled by a real numberThe original vector is (2, 1). With scale 1, the result is (2.0, 1.0).x₁x₂0v = (2, 1)αv
αv = (2.0, 1.0)

A positive scale preserves the direction.

The course map

One idea builds on another.

Begin with ten complete foundation lessons in modules 0 and 1. Each connects an explanation to an experiment and a prediction. The remaining course is in development.

00

Supplement

Math starter kit

Algebra, functions, coordinates, and the language of mathematics.

Numbers that tell a story →Functions are machines →Give a point an address →Read symbols as sentences →Change, one small step at a time →How do you know it is true? →
6 lessons ready
01

§1–2

Getting started & notation

Read mathematical symbols and check the shape of an expression.

The math behind a prediction →A field guide to the symbols →Know what kind of thing you have →Let dimensions catch mistakes →
4 lessons ready
02

§3.1–3.5

Vectors & spaces

Build intuition for vectors, distance, inner products, and projection.

What can you build from two directions? →Vectors as coordinates and displacements →Which sets keep every linear combination? →What must a linear map preserve? →Why do matrix columns describe a map? →What disappears, and what can you reach? →How can distance define a limit? →Does changing length change convergence? →How does a product measure alignment? →How large can an inner product be? →Why is the perpendicular foot the closest point? →
11 lessons ready
03

§3.6–3.11

Understanding matrices

Explore eigenvectors, symmetry, and the geometry of quadratic forms.

Which directions stay on the same line? →Which changes leave the diagonal sum alone? →When does a transformation flatten area? →Which matrices preserve length and angle? →Can a symmetric map be split into three simple steps? →Which direction gives the largest quadratic value? →When is every nonzero direction uphill? →Why does a larger eigenvalue make a shorter ellipse axis? →
8 lessons ready
04

§3.12–3.17

SVD & matrix tools

Connect subspaces, matrix norms, low-rank approximation, and pseudoinverses.

What does a matrix stretch? →Which part of an input survives? →How much can a matrix amplify a vector? →How much can you discard? →Can you undo a map that loses information? →How do columns and outer products build a matrix? →
6 lessons ready
05

§4.1–4.7

Calculus & optimization

Understand gradients, curvature, the chain rule, and local minima.

Where are you allowed to look for a minimum? →Which direction changes the value fastest? →What linear map describes a nonlinear change nearby? →How does curvature change a step? →Why does a quadratic gradient contain a transpose? →How does a change travel through a composition? →How accurate is the local picture? →When does a stationary point really minimize? →
8 lessons ready
06

§4.8

Convexity

Learn what convexity tells us about an optimization problem.

Planned
07

§5.1–5.3

Probability & randomness

Reason about events, random variables, and joint distributions.

Planned
08

§5.4–5.8

Summaries & estimation

Connect expectation, covariance, likelihood, and Bayesian estimation.

Planned
09

§5.9

Gaussian geometry

See how probability, eigenvectors, and ellipses fit together.

Planned
10

Supplement + p.47

Projects & references

Put the mathematics to work in guided experiments.

Planned