Shown here is a split-flap single-digit display in action. The display is designed in sketchup, printed using a laser cutter on birch, and made of absolutely nothing but glued wood. The motor is a three-wire switched reluctance motor, which I control by energizing the three coils independently using an RBBB Arduino-like microcontroller and a ( Read more... )

Now that the qualifying round for Google Code Jam is over, I'd like to share my solution to the third problem ( Read more... )

Never thought I'd see the day when suits talk amongst themselves about some stuff I made:

Property Portal Watch on Transit Maps - A website all about real estate websites.
AIM Group on Transit Maps - Site is bar-graph themed, includes tabs for "Real Estate" and "Automotive ( Read more... )

This afternoon I tidied up and released something I'd made a little while ago, a way of driving the Processing renderer from inside Python. Here it is:

PRender

PRender was made as a map renderer. So I made some of those:

Here's a map of my trip from my house to PCC, with the width of the line proportional to slowness:


( Read more... )

This evening I made specifiable at runtime some of the parameters previously built-in to the transit trip planner - for instance, the speed the transit rider is able to move along the street, to transfer between stops or walk to the origin or destination stops. Here's the transit reachability map for the same origin at the same time of day, for ( Read more... )

Visualization of the shortest path tree on a weighted directional graph representing a social network, with respect to Michelle. The weight of a "friendship" is 1/((number of mutual friends + 1) / number of frinds) - basically, the strength of your friendship is assumed to be proportional to the number of mutual friends you have with that person ( Read more... )

I valgrinded the hell out of Graphserver today, completely shoring up the remaining memory leaks I was getting on street-based shortest path trees. It continues to return city-sized SPTs in about a tenth of a second, which is heartening. I'll need to figure something out for truly large, state-sized road networks, though. But that's for later. ( Read more... )

I've said this before, but Valgrind is cool. Here's a basic example of how to use it to find memory leaks in a C program:

Here's a file, "vhelloworld.c"

#include "stdio.h ( Read more... )

Growing shortest path tree from an intersection just south of the University Bridge in Seattle. Using Graphserver and OSM street data. Visualization using Processing. Nino Walker and I have made some great progress in writing a set of Python wrappers for the Graphserver library, making things like this relatively straightforward to implement. ( Read more... )

WhatTheMetro has a post in Seattlest

Someone who is not me wrote python wrappers for Graphserver. I'm writing a unit testing framework for it right now, tracking down some segfaults.