This literate essay develops an implementation of a type called `Differential`. A `Differential` is a generalization of a type called a ["dual number"](https://en.wikipedia.org/wiki/Dual_number), and the glowing, pulsing core of the SICMUtils implementation of forward-mode automatic differentiation.
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Functional Numerical Methods
This page contains a literate-programming exported version a definite-integral package I built into SICMUtils, a Clojure(script) based computer algebra system based on Gerald Sussman's scmutils. (Beware the buzzwords...) I expect that this post will fission into a full series, with a bit of explanation about how each piece fits
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Power Series, Power Serious
This post spawned from work I've been doing on the SICMUtils library; I've just released 0.13.0 and I hope you'll give it a try. SICMUtils is the engine behind the wonderful "Structure and Interpretation of Classical Mechanics", an advanced physics textbook by Gerald Sussman of SICP fame. I'm
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How to Publish CLJSJS Jars to Clojars
I've been doing a lot of work in Clojurescript lately, and the time finally came to pull in my first vanilla Javascript dependency. The default way to do this seems to be the CLJSJS project. CLJSJS publishes many Javascript packages in a form that you can consume from a Clojure
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Optics and the Principle of Least Time
(This is a writeup of Exercise 1.3 from Sussman and Wisdom's "Structure and Interpretation of Classical Mechanics". See the solutions repository for more.) Law of Reflection Geometry Calculus Law of Refraction Calculus Geometry The problem explores some consequences for optics of the principle of least time. The
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Half Angles from Euler's Formula
I've been reading the lovely Visual Complex Analysis by Tristan Needham, and the visual-style proofs he's been throwing down have been wonderful and refreshing. I'll write more about this book and its goals later, but I was inspired this AM to write up a proof of the half angle identities
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Niwot's Challenge 2018 Race Report
I feel like I'm never going to publish this damned thing... so here it is, in bullet point form. Maybe I'll tidy it up some day. Niwot's Challenge, a very fun race out in South Platte. Jason invited me to this damned thing last week... Text from Jason: "Free Sat?
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Niwot's Challenge 2019 Race Report
Well, I can honestly say, now, close to a year after the event, that I don't remember this event in the furious detail that characterizes my usual race reports. How lucky! We're not supposed to talk about the Niwot's Challenge at all. I ran this race in 2019 for the
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Basis Changes for Linear Transformations
A 1-act sketch via Apple Pencil, for your viewing pleasure. Happy to link to further references or sketch this out in more detail — let me know in the comments if this is illuminating. Check it out below, or click here for a direct image link to stare at a big
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Book: The Second Mountain
I had a hard time with this book; it showed up in the TED book club mailing months ago, and I went into my reading primed to love the message, which is concise and persuasive... but maybe so persuasive on its own that the book feels like 300 pages of
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Taylor Series and Imaginary Numbers
I wanted to share some of the intuition I've been developing around complex numbers; some of the resources that have been helpful, for understanding why anyone would come up with an idea like $i$, the square root of -1, and then build an entire number system on top of it.
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Entropy: Combinations and Permutations
In my ongoing quest to lay a more solid foundation for this new, strange life as a machine learning "researcher", I've been going through various foundational concepts and ideas and trying to build up rock solid intuitions that I can lean on for years. (Why the hell didn't I do
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Book: On Having No Head
What a strange, fantastic little book! I recently read Douglas Harding's "On Having No Head" after hearing Sam Harris mention the book in one of "Waking Up" meditations, and then many times on subsequent podcasts. The book is a long look at an insight that blew Harding's mind — from the
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Windshield and Windows Attached
The RV10 has windows! And a windshield! I've got everything attached and mostly cleaned up. Here's what it looks like now: I used three tubes of Lord 7545 A/E adhesive from Aerosport Products, one for each pair of side windows and a full tube for the windshield. The process
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Spring Clips and Stage Time
I'm out here working on the plane today - I haven't made it out much, lately, but I'm in the garage spending the time. This project will end up taking roughly five years, three years longer than I thought it might when I started. I've gone through so many oscillations
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