John Cook: Why and How People Use R
R is a strange, deeply flawed language that nevertheless has an enthusiastic and rapidly growing user base. What about R accounts for its popularity in its niche? What can language designers learn from R's success?
Project Sentry Gun
Welcome to Project Sentry Gun, home to the most versatile sentry gun on the web!
This sentry gun autonomously tracks, aims, and shoots at targets, using:
An airsoft or paintball gun
A webcam to find targets
A computer to process the video feed and aim the gun
Servo motors to physically aim the gun and squeeze the trigger
A sturdy tripod base
A microcontroller to interface between the computer and the servo motors
Fully open-source code
Lots of camo paint
The end result is a paintball/airsoft spewing robot, that can turn the tides of any match.
Amber, formerly known as Jtalk, is an implementation of the Smalltalk-80 language. It is designed to make client-side development faster and easier. It allows developers to write client-side heavy web applications in Smalltalk.
Amber includes an integrated development environment with a class browser, workspace, transcript, object inspector and debugger.
a jQuery plugin that annotates text with Morse Code
William Cook's Fusings: Enso Introduction
Structures in Ensō are a specialized kind of graph, whose nodes are either primitive data or collections of observable properties, whose values are either nodes or collections of nodes. From a programming language viewpoint this may seem an odd choice for data representation. However, it is essentially the Entity-Relationship (ER) model, also known as Information Models, which is widely used in the design of relational databases and is also the basis for Class Diagrams in the Unified Modeling Language (UML), which describe the structure of networks of objects. The key point is that structures in Ensō are viewed holistically as graphs, not as individual values or traditional sums-and-products data structures.
Mozart's Musikalisches Würfelspiel
In 1787, Mozart wrote the measures and instructions for a musical composition dice game. The idea is to cut and paste pre-written measures of music together to create a Minuet.
This site is an implementation of such a game. The music and table of rules for this game appear to have been published anonymously in 1787, and interestingly, the table of rules for this Minuet is identical to Mozart's. However, it is not clear who the composer of these measures is.
There are 176 possible Minuet measures and 96 possible Trio measures to choose from. The result of a dice roll is looked up in a table of rules to determine which measure to play.
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.
Packet Forth (PF) is a scripting language for real-time video processing and graphics generation. PF is now quite stable and usable, but remains a bit of an odd duck in the land of open source video processing tools. I use it mainly as a prototyping tool for C-based signal processing.
PF is a concatenative programming language which takes ideas from Forth, Joy, PostScript, Factor, and Lisp. As opposed to its memetic parents, PF is not intended as a general purpose programming language, but a scripting language that glues together black box processing primitives and relevant open source libraries
RepRap is short for Replicating Rapid-prototyper. It is the practical self-copying 3D printer shown on the right - a self-replicating machine. This 3D printer builds the parts up in layers of plastic. This technology already exists, but the cheapest commercial machine would cost you about €30,000. And it isn't even designed so that it can make itself. So what the RepRap team are doing is to develop and to give away the designs for a much cheaper machine with the novel capability of being able to self-copy (material costs are about €500). That way it's accessible to small communities in the developing world as well as individuals in the developed world.