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Topics /
Math & Algorithms
The most popular blog posts about math & algorithms on Hacker News. 132 posts.
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Music theory for nerds
Not music nerds, obviously. I don’t know anything about music. I know there are letters but sometimes the letters have squiggles; I know an octave doubles in pitch; I know you can write a pop song with only four chords. That’s about it. The rest has always seemed completely, utterly arbitrary. Why do we have twelve…
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Page Dewarping
Flattening images of curled pages, as an optimization problem.
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4-bit calculator made from cardboard and marbles
Might not be the most reliable or useful contraption but it's definitely a fun one.
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How is NSA breaking so much crypto? (2015)
There have been rumors for years that the NSA can decrypt a significant fraction of encrypted Internet traffic. In 2012, James Bamford published an article quoting anonymous former NSA officials stating that the agency had achieved a “computing breakthrough” that gave them “the ability to crack current public…
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Skip Lists Done Right
Skip lists are a wonderful data structure, but it is hard to get\ right. This blog post presents various techniques to optimize and\ improve the implementation of skip lists.
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Habits of highly mathematical people
The most common question students have about mathematics is “when will I ever use this?” Many math teachers would probably struggle to give…
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How Kalman Filters Work
This articles describes how Kalman filters and other state estimation techniques work, focusing on building intuition and pointing out good implementation techniques.
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A Beginner's Guide to Understanding Convolutional Neural Networks
Engineering at Forward | UCLA CS '19
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Just A New Fractal Detail In The Big Picture (2015)
When the central heating takes effect I'll get up and make myself some tea and porridge to which I'll add some nuts and fruit. I'll switch on The World Service to hear the news, and then make a few phone calls about damp-proofing. And I'll probably plant the daffodil bulbs for Spring (it says on the packet they should…
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Image Kernels explained visually
An image kernel is a small matrix used to apply effects like the ones you might find in Photoshop or Gimp, such as blurring, sharpening, outlining or embossing. They're also used in machine learning for 'feature extraction', a technique for determining the most important portions of an image. In this context the…
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Tools for thought: graphical algebra and Fourier analysis
" I think a lot of mathematics is really about how you understand things in your head. […]
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The Rule of 72 (2007)
The Rule of 72 is a great mental math shortcut to estimate the effect of any growth rate, from quick financial calculations to population estimates. Here’s…
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A beginner's guide to Big O notation (2009)
Thoughts on software engineering from Rob Bell
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Some of the most important deep learning papers
Engineering at Forward | UCLA CS '19
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2^74207281-1 is Prime
GIMPS has discovered a new Mersenne prime number: 2^74207281-1 is prime! Discovered: 2016 Jan 07
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Regular Expression That Checks If A Number Is Prime
Join Illya Gerasymchuk on his new blog as he explores blockchain, DeFi, Zero-Knowledge cryptography, AI, and finance.
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Statistical Mistakes and How to Avoid Them
You can get CS papers published with shoddy statistics, but that doesn’t mean you should. Here are three easy ways to bungle the data analysis in your evaluation section: don’t even try to use statistics when you really ought to; misinterpret an inconclusive statistical test as concluding a negative; or run too many…
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Finger Trees: A Simple General-Purpose Data Structure (2006)
Finger Trees: A Simple General-purpose Data Structure
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The rectangularness of countries
What is the most rectangular country?
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Why squared error? (2014)
its computational convenience • connections to the Gaussian distribution • differentiability and basis independence • why not squared error • absolute-error methods
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Image unshredder by simulated annealing (2015)
On another page , I unleash the simulated annealing algorithm on a toy problem. It generates an image full of random colorful pixels, and rearranges the pixels so that similar colors are near each other.
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Decoding the Thought Vector
Neural networks have the rather uncanny knack for turning meaning into numbers. Data flows from the input to the output, getting pushed through a series of transformations which process the data into increasingly abstruse vectors of representations. These numbers, the activations of the network, carry useful…
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The Elegance of Deflate
A little while back I found need of a PNG loader for a small project of mine . Being a complete tool I of course decided to write my own -- after all, why save yourself effort when there are still wheels waiting to be reinvented? You can check the source to the inflater code here if you so like - it's quite cleanly…