151
Reservoir Sampling
Choosing fairly when you don't know how many you're choosing from.
New
The latest blog posts to take off on Hacker News. 238 posts.
152
Progress toward fusion energy gain as measured against the Lawson criteria
Today we’ve released a pre-publication version of an update to our 2022 paper “Progress toward fusion energy breakeven and gain as measured against the...
153
154
Geometrically understanding calculus of inverse functions (2023)
The Legendre transformation tells you how the inverse map acts on integrals
155
Unparalleled Misalignments
This is a list of Unparalleled Misalignments, pairs of non-synonymous phrases where the words in one phrase are each synonyms of the words in the other. I've maintained this list since 2018; attributions (when known) can be seen on hover.
156
157
Bloom Filters
The original motivation for the creation of Bloom filters is efficient set membership, using a probabilistic approach to significantly reduce the time and space required to reject items that are not members in a certain set.
158
Derivation and Intuition behind Poisson distribution
Made in Notion, the connected workspace where AI agents and teams organize docs, projects and knowledge together.
159
Reversible computing with mechanical links and pivots
With the concern that “Moore’s Law is dead,” new interest has grown for unconventional forms of computing. This includes:
160
An illustrated guide to automatic sparse differentiation
In numerous applications of machine learning, Hessians and Jacobians exhibit sparsity, a property that can be leveraged to vastly accelerate their computation. While the usage of automatic differentiation in machine learning is ubiquitous, automatic sparse differentiation (ASD) remains largely unknown. This post…
161
162
Shortest-possible walking tour to 81,998 bars in South Korea
We have solved a traveling salesman problem (TSP) to walk to 81,998 bars in South Korea. The problem was created using the Open Source Routing Machine (OSRM) to build a table of the 3,361,795,003 point-to-point travel times, one for each pair of bar locations. Our computation produced a tour together with a proof that…
163
Collatz's Ant
This is a brief continuation of a previous post ( Repo ), which introduced such visualization for collatz sequences based on Langton’s Ant .
164
Are polynomial features the root of all evil? (2024)
High-degree polynomial features aren’t inherently unstable: the power basis and unscaled inputs are. This post shows how regularization and Bernstein polynomials make polynomial regression behave.
165
Algebraic Semantics for Machine Knitting
As programming languages researchers, we’re entitled to a certain level of mathematical rigor behind the languages we write and analyze. Programming languages have semantics , which are definitions of what statements in the language mean. We can use those semantics to do all sorts of useful things, like error…
166
100 Years to Solve an Integral (2020)
The integral of sec(x) is well known to any beginners calculus student. Yet this integral was once a major outstanding maths problem. It was first introduced...
167
168
Dumb statistical models, always making people look bad
This is Jessica. In my Prediction for Decision-making class last quarter we talked about human predictions and decisions relative to algorithmic ones. This led to a discussion about why it’s often hard to demonstrate the value of human knowledge once you have a decent statistical model.
169
A cute proof that makes e natural
Po-Shen Loh explains why Euler's number e is natural using only precalculus: one exponential curve has tangent slope 1 at the y-axis, which leads to the compound interest limit.
170
The Halting Problem is a terrible example of NP-Harder
It's a justifiable copout, but it's still a copout.
171
An Introduction to Stochastic Calculus (2022)
Through a couple of different avenues I wandered, yet again, down a rabbit hole leading to the topic of this post. The first avenue was through my main focus on a particular machine learning topic th
172
What Is Entropy?
People say many things about entropy: entropy increases with time, entropy is disorder, entropy increases with energy, entropy determines the arrow of time, etc.. But I have no idea what entropy is, and from what I find, neither do most other people. This is the introduction I wish I had when first told about entropy…
173
Monte Carlo Crash Course: Sampling
In the previous chapter, we assumed that we can uniformly randomly sample our domain. However, it’s not obvious how to actually do so—in fact, how can a deterministic computer even generate random numbers? 1
174
Writing my own dithering algorithm in Racket
My journey implementing a new dithering algorithm in the Racket programming language.
175
How much oranger do red orange bags make oranges look?
Look at this orange: Now look at this orange: It’s the same orange. But, look how much more orange it looks with the red mesh on top of it: If you buy bags of oranges (at least at many places in the US), they frequently come in this red mesh bag. This bag makes the oranges look more orange. Oranger. Here’s what that…
176
The Bitter Prediction
The Ivory Tower is a blog about software engineering and development philosophy by Anders Sundman.
177
Bilinear interpolation on a quadrilateral using Barycentric coordinates
A new algebraic method for hardware-accelerated bilinear interpolation on convex quadrilaterals is presented, using the Barycentric coordinate feature of modern GPUs.
178
Parser Combinators Beat Regexes
Someone online was solving Advent of Code problems, and had a question about last years’ day 3 . They had a working solution using regular expressions (regexes) on String values, but they wanted to use ByteString values instead for performance reasons. They were surprised, however, that there seems to be a lack of…
179
Solving a “Layton Puzzle” with Prolog
I have a lot in the works for the this month's Logic for Programmers release. Among other things, I'm completely rewriting the chapter on Logic Programming...
180
Analytic Combinatorics – A Worked Example
Chris Grossack's math blog and professional website.