This text is designed to accompany your study of introductory digital signal processing.1 It’s an eccentric piece of not-so-rigorous literature with a preoccupation for explaining things using interactive visualizations, animations and sound.2 My goal is to explain the Discrete Fourier Transform using a miniature curriculum which leverages your ability to learn concepts and absorb information visually instead of linguistically.3 My hope is that these glyphs become slightly more comprehensible and slightly less intimidating after reading the subsequent 30 or so pages.4
Unit Circle Trigonometry - haitham
An interactive sketch for visualizing sine and cosine functions with the unit circle
Circle of Fifths: The Key to Unlocking Harmonic Understanding
The circle of fifths is arguably the most helpful way of visually organizing the 12 chromatic pitches for learning music theory. Enjoy this lesson excerpt.
Sine, Saw, Square, Triangle, Pulse: Basic Waveforms in Synthesis and Their Properties
Learn the properties of 5 basic waveforms in sound synthesis to use their full potential in your synthesizer performance or design.
Doing maths in CSS
sin(), cos(), atan2() landed in CSS in 2023. You can now place elements in circles, arcs, and spirals with pure CSS, no JavaScript, no libraries. Here's how the math works.
Mystical
I wanted to make a programming language that resembled magical circles. This is more like a way to write PostScript that looks like a magical circle, but I will refer to it as Mystical in this document.
The Circle Of Fifths: A Complete Guide
The circle of fifths is an incredible tool that has many different uses when it comes to music theory. It can help us with everything from knowing what chord
Derivatives of Spherical Harmonics
Christoph Peters. 2025–06 in High-Performance Graphics 2025. Poster.
Angular最新トピックとテクニックをng-japan代表のlacoさんに聞いてきた！（前編）
こんにちは、編集長の白石です。ぼくは、自社で運営と開発をしているTechFeedというエンジニア向けニュースアプリにAngular（とIonic）を採用していることもあり、Angularの行方には強く
Pluck
This is an interactive string simulator that uses basic Fourier math to generate audio & visuals according to where on the string you pluck from. The audio math is done on the GPU in WebGL
circmoji - Bluesky Emoji Circles
Pure CSS halftone patterns: dots, lines, circles
A project overdue. As an 80's/90's kid, I was obsessed with printing technology - and especially halftone patterns. I've long theorized that these pat
What is a harmonic? An interactive comic about additive synthesis
Where do harmonics even come from? Learn about additive synthesis and play with interactive string modes.
The virtuous circle
The virtuous circle is the most powerful pattern in developer tooling. And it's the myth of the 10x developer that makes it hard to see.
About these notes
Hi! I’m Andy Matuschak. You’ve stumbled upon my working notes. They’re kind of strange, so some context might help.