April 26, 2013

Jane Jacobs and Global Cities Presentation at the California Geographical Society

I gave a presentation on the connections between Jane Jacobs and Global Cities Theory at the California Geographical Society 2013 conference. The slides from the presentation are on the Publications page.

January 20, 2013

Organizing my Research

As a follow-up to my recent post about organizing my library, this post talks about the system I’ve come up with for organizing my research.

I was starting a new research project, and I realized that writing my bibliography and managing my citations manually wasn’t going to be good enough. I needed a reference manager of some sort. My librarian suggested I try Mendeley, and it has become the core of my reference-management workflow.

December 31, 2012

Organizing My Library

My personal library of books has been growing rather quickly of late, and a few months ago I realized I need to organize it. I decided to organize my books using the Library of Congress classification system. That is the system in use by most academic libraries in the United States, and it was familiar to me. I could have used the Dewey Decimal System as well. Library of Congress does have the advantage of covering both fiction and non-fiction. I initially learned how to do this using this post which goes more in-depth about the physical organization of items.

September 15, 2012

A Simple Model of Automobile Travel Time

For some personal research I’m working on, I’m using OpenTripPlanner for automobile routing. I’ve already applied speed limits to the routing algorithm, but that’s only part of accurately modeling automobile travel time. While for a cyclist or a pedestrian, the amount of time spent actually moving at full speed may be the lion’s share of their journey, for an automobile this is not true. Especially in city traffic, it’s likely that a large part of the time is spent waiting at intersections, accelerating, or moving through congestion (or not moving through congestion).

July 7, 2012

Running an Emacs Server

I’ve just begun running an Emacs Server process on my computer; now, instead of having many emacs processes running when I’m editing code, I have just one. Each emacs window can access the buffers in every other one. Also, emacs now starts much more quickly than it did before (because it’s actually already running). Here’s how it’s done.

The first thing to do is to add this line at the end of your .emacs:

June 16, 2012

How I Migrated to Jekyll

This is a short post about how I migrated this blog from its previous home on WordPress to its new home here.

s o u r c e c o d e

syntax and to convert the the proper Pygments syntax. I also modified it to move all of the images locally to my blog. I then edited each post manually to remove strange characters that were left behind (presumably a charset issue). I am using rdiscount and SmartyPants to get typographically-correct quotes—and dashes.

June 16, 2012

Migrating to Jekyll

Welcome! I’m currently migrating this blog to Jekyll; comments should be restored soon.

April 29, 2012

Measuring Urban Mobility and Accessibility Using OpenTripPlanner Analyst

I presented a poster on OpenTripPlanner Analyst at the California Geographical Society 2012 conference. Here are the poster and some companion materials:

Poster (PDF, 1.7MB)—the poster itself.
Maps (PDF, 7.8MB)—all of the maps that were present on the poster. Some were somewhat small, here is a PDF of all of them in vector format, suitable for stretching across the sides of large buildings.
Methodology (PDF, 207KB)—the methodology behind making each of the figures. This is a more in-depth, technical explanation than was provided on the poster itself.

April 1, 2012

Elevators in OpenTripPlanner

I’ve been working on the OpenTripPlanner project quite a bit lately. One thing I did a month or so ago was to implement elevator support in the routing engine. I decomposed OSM nodes tagged highway=elevator by their constituent levels, and built edges between them to represent boarding, riding on, and alighting from an elevator. I was very impressed with the friendliness and responsiveness of the community.

One challenge was parsing OSM levels. They can come from multiple sources—level_map relations, level tags or layer tags. I wanted to support all of these, or any combination (on a single elevator). I originally did this by noting the source and adding 0, 1000 or 2000 to the level, but Andrew Byrd has made an OSMLevel class which handles this much more neatly. Level maps allow levels to be named, which is quite nice: “take elevator to garage” instead of “take elevator to -1.” So, for all OSM mappers out there, here is a quick guide to making routable elevators:

April 1, 2012

BART Shocker: First Inner-Core Infill Station Since Embarcadero

BART shocked Bay Area transit enthusiasts this morning with an announcement that it plans to build a new infill station, to serve all San Francisco lines, at Treasure Island.

“Treasure Island has long been underserved by transit,” said a BART employee, who is heading the project and acting as a liaison between the agencies involved. “The residents have long been frustrated that they live within a mile of rail rapid transit but cannot access it.”