The Pac-Man Dossier
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The Pac-Man Dossier
This web page is dedicated to providing Pac-Man players of all skill levels with the most complete and detailed study of the game possible. New discoveries found during the research for this page in December 2008 have allowed for the clearest view yet of the actual ghost behavior and pathfinding logic used by the game.

Robot Traders
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Market Data Firm Spots the Tracks of Bizarre Robot Traders
The trading bots visualized in the stock charts in this story aren't doing anything that could be construed to help the market. Unknown entities for unknown reasons are sending thousands of orders a second through the electronic stock exchanges with no intent to actually trade. Often, the buy or sell prices that they are offering are so far from the market price that there's no way they'd ever be part of a trade. The bots sketch out odd patterns with their orders, leaving patterns in the data that are largely invisible to market participants.

Delving a connected cavern
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Delving a connected cavern - RogueBasin
Both various maze (spanning tree) algorithms and cellular automata have been applied for generating dungeons in roguelikes. The algorithm described below is somewhere in between; it is related to the randomized Prim's and the growing tree maze algorithms; it has also a lot in common with cellular automata, although the cells are not processed simultaneously.

Quantum Algorithms A Different View
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Quantum Algorithms A Different View « Gödel’s Lost Letter and P=NP
Today I plan to try to explain the power of quantum algorithms, but do it in my way. I hope this “explanation” will help you understand their power, yet avoid some of the complexities with the usual explanations.

PageRank Explained with Javascript
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PageRank Explained with Javascript
PageRank is a measure of network centrality with some tweaks made that are specific to web browsing, as we've discussed above. Since we are pretty much only dealing with matrices at this point we'll refer to this as eigenvector centrality.

Haversine formula in JavaScript
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Calculate distance and bearing between two Latitude/Longitude points using Haversine formula in JavaScript
This page presents a variety of calculations for latitude/longitude points, with the formulæ and code fragments for implementing them.

All these formulæ are for calculations on the basis of a spherical earth (ignoring ellipsoidal effects) – which is accurate enough for most purposes.

Damn Cool Algorithms: Levenshtein Automata
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Damn Cool Algorithms: Levenshtein Automata
The basic insight behind Levenshtein automata is that it's possible to construct a Finite state automaton that recognizes exactly the set of strings within a given Levenshtein distance of a target word. We can then feed in any word, and the automaton will accept or reject it based on whether the Levenshtein distance to the target word is at most the distance specified when we constructed the automaton. Further, due to the nature of FSAs, it will do so in O(n) time with the length of the string being tested.

A Stick Figure Guide to the AES
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Moserware: A Stick Figure Guide to the Advanced Encryption Standard (AES)
A play in 4 acts. Please feel free to exit along with the stage character that best represents you. Take intermissions as you see fit. Click on the stage if you have a hard time seeing it. If you get bored, you can jump to the code. Most importantly, enjoy the show!

Chroma-Hash revisited
Chroma-Hash revisited
Chroma-Hash allows you to quickly compare the contents of two secure text fields. It’s common for a signup flow to ask you to type your password twice (to make sure you didn’t mistype it). With this visualization, a user can instantly check to see if what she typed was the same each time, without having to submit the form.

Packrat Parsing and Parsing Expression Grammars
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Packrat Parsing and Parsing Expression Grammars
Parsing expression grammars (PEGs) are an alternative to context free grammars for formally specifying syntax, and packrat parsers are parsers for PEGs that operate in guaranteed linear time through the use of memoization.