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The latest blog posts to take off on Hacker News. 216 posts.
Introduction to Bayesian Filter
Restate Some Basic Concepts and Math in Bayesian Filter
Taleb is wrong about IQ
Investigation of Talebs claims about IQ using real data.
Alpha Compositing
Interactive article explaining alpha compositing concepts.
Math versus Dirty Data
At Google, our organization designs, owns, and maintains a number of optimization models that automate the planning of Google’s datacenter growth and health. As is pretty standard in supply chain optimization and planning, these models are often integer linear programs. It’s a core competency of operations research…
Visual Information Theory (2015)
I love the feeling of having a new way to think about the world. I especially love when there’s some vague idea that gets formalized into a concrete concept. Information theory is a prime example of this.
Mitchell Feigenbaum (1944–2019), 4.66920160910299067185320382…
Stephen Wolfram shares his memories of mathematical physicist Mitchell Feigenbaum. Also a detailed discussion of his work and big discovery of a universal constant for functions approaching chaos via period doubling.
L2 Regularization and Batch Norm
This blog post is about an interesting detail about machine learning that I came across as a researcher at Jane Street - that of the interaction between L2 r...
A Grimoire of Functions
I'm the kind of person who reads encyclopedias front to back just for fun, and I've been fascinated by mathematical special functions at least since my first encounter with the gamma function as a teenager. My work implementing numerical and symbolic algorithms in mpmath , Arb and other software projects during the…
Dungeon Generation in Diablo 1
Diablo1 is a classic 1996 hack and slash rogue-like. several fans took it upon themselves to reverse-engineer the source code. I began a week long deep dive into how exactly did lead developer, Dav…
Think in Math, Write in Code
Programmers love to discuss programming languages. We not only debate their technical merits and aesthetic qualities, but they become integrated into our personal identities, along with the values and traits that we associate with them. Some even defend a form of Linguistic Determinism that thinking is confined to…
Cities: Skylines Is Turing Complete
(Non-clickbait title: building a 4-bit adder in Cities:Skylines.)
Steve Wozniak's floating point routines for the 6502
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The Riemann Hypothesis Says 5040 Is the Last
Note: These pages make extensive use of the latest XHTML and CSS Standards . They ought to look great in any standards-compliant modern browser. Unfortunately, they will probably look horrible in older browsers, like Netscape 4.x and IE 4.x. Moreover, many posts use MathML, which is, currently only supported in…
It’s Time for Some Queueing Theory
Queueing theory is the scientific study of waiting in line. It can apply to familiar lines like those at the grocery store or bank but also to things like web s
Real-world dynamic programming: seam carving
Dynamic programming has a reputation as a technique you learn in school, then only use to pass interviews at software companies. Indeed, most developers do not regularly work on problems where dynamic programming is needed. Ultimately, dynamic programming is a technique for efficiently solving problems that can be…
What is ergodicity? (2016)
Why are election polls often inaccurate? Why is racism wrong? Why are your assumptions often mistaken? The answers to all these questions and to many others have a lot to do with the non-ergodicity…
Adventure Games and Eigenvalues (2017)
Do adventure games have dead ends? The author of The Teeny Tiny Mansion proves the absence of dead ends in that game via formal verification (in particular, with the help of the cbmc model-checking program ). Here I’ll demonstrate how to prove the same thing via Markov theory. The Markov approach requires more…
Logistic Regression from Bayes’ Theorem
In this post we’ll explore how we can derive logistic regression from Bayes’ Theorem. Starting with Bayes’ Theorem we’ll work our way to computing the log odds of our problem and the arrive at the inverse logit function. After reading this post you’ll have a much stronger intuition for how logistic
Quantum transitions take time – the news is its experimental demonstration
A number of people have asked me to weigh in on this story in Quanta Magazine (based on this paper [ PDF version ] and also reported in t...
Solving Programming Puzzles Without Using Your Brain
This post is a write-up of a solution to part of a programming puzzle I did yesterday. It’s a little different than the usual “solution + theory” approach, though: I’m going to talk about the actual steps you’d need to take to get to the solution (i.e. what to google, what intermediate code looks like, etc.). Often…