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Playing with model trains and calling it graph theory
You’ve probably played with model trains, for instance with something like the Brio set shown below.1 And if you’ve built a layout with a model train set, yo...
New
The latest blog posts to take off on Hacker News. 2,391 posts.
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Mathematical Jargon Failures
From the highly eclectic blog of Mark Dominus
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Everything Is Correlated
Anthology of sociology, statistical, or psychological papers discussing the observation that all real-world variables have non-zero correlations and the implications for statistical theory such as ‘null hypothesis testing’.
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Meditations on Moloch (2014)
I. Allen Ginsberg’s famous poem on Moloch:What sphinx of cement and aluminum bashed open their skulls and ate up their brains and imagination? Moloch! Solitude! Filth! Ugliness! Ashcans and u…
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P = NP Proofs: Advice to claimers
Advice to claimers The Claimers The Claimers are a gang on the hit AMC television series The Walking Dead. They are the main antagonists in the second half of the zombie-apocalypse show’s Sea…
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I found two identical packs of Skittles among 468 packs
This article was discussed on Hacker News, and was cited in The Mathematical Gazette. Introduction This is a follow-up to a post from earlier this year discussing the likelihood of encountering two…
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How the quantum search algorithm works
An explanation of how the quantum search algorithm works, & introduction to the design of quantum algorithms
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Graphical Introduction to Dynamic Programming
I’ve been helping a friend understand dynamic programming (DP for short), so I’ve been on the lookout for good resources. The topic is covered all across the web, but I found many of them focused on the code, and not enough on the beautiful visualizations that shed light into how DP works.
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What Is a Manifold?
In machine learning, the term manifold is thrown around a lot—in fact, there’s even a branch of machine learning dealing with learning the structure of manifolds. Said branch is aptly named manifold learning . Inspired by fantastic visualizations of shapelet mining algorithms , this post aims to give a visual…
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Random Forests for Complete Beginners
The definitive guide to Random Forests and Decision Trees.
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Explaining Sex Rate Changes
According to the Post, polls say 28% of US men age 18-30 report not having sex in the last year, almost 3 times as many as a decade ago.
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Second-Order Thinking: What Smart People Use to Outperform (2016)
Second-order thinking is a mental model that smart people like Warren Buffett & Howard Marks use to avoid problems. Read this article to learn how it works.
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93% of Paint Splatters Are Valid Perl Programs
TLDR: read the paper and view the gallery of pretty Perl programs. In this paper, we aim to answer a long-standing open problem in the programming languages community: is it possible to smear paint on the wall without creating valid Perl?
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Loop invariants can give you coding superpowers
A loop invariant is a simple yet powerful tool for designing, testing, modifying, documenting and proving code correct.
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Why Do Buses Bunch?
Created by Lewis Lehe (of Setosa and UC Berkeley Trans. Eng. ) with design and art by Dennys Hess . Thanks to Ian Johnson for good advice. Tools: d3 , Angular Material , Coffeescript , Browserify , Gulp and Five-Hour Energy Drink .
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Common statistical tests are linear models
By Jonas Kristoffer Lindeløv ( blog , profile ). Last updated: 28 June, 2019 (See changelog ). Check out the Python version and the Twitter summary .
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US Army applying new areas of math
Many times on this blog I've argued that the difference between pure and applied math is motivation. As my graduate advisor used to say, “Applied mathematics is not a subject classification. It's an attitude.” Traditionally there was general agreement regarding what is pure math and what is applied. Number theory and…
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Quantum Computing for the Curious
Presented in an experimental mnemonic medium that makes it almost effortless to remember what you read
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Backpropogation Is Just Steepest Descent with Automatic Differentiation (2013)
Preface The intended audience of this article is someone who knows something about Machine Learning and Artifical Neural Networks (ANNs) in particular and who recalls that fitting an ANN required a…
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A Short Intro to Constraints
The essence of constraint is projection.
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How I Learned to Love Algebraic Geometry
A more polished version of this article appeared on Nautilus on 2019 February 28. This version has some more material. How I Learned to Stop Worrying and Love Algebraic Geometry In my 50s, too old …
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Dynamic Programming for Technical Interviews
Probably the first in a multi-part series on DP.
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Principal component analysis: pictures, code and proofs (2018)
The code used to generate the plots for this post can be found here.
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The Essence of Datalog (2018)
Mistral Contrastin's thought bubble, blog, and personal revelations.