A History of Philadelphia Churches through Maps, Part II

In the first part of this series, I discussed how distribution of churches across the Philadelphia region ties to population density, suggesting that visual patterns in maps can be used to better understand slices of our history. This material isn’t particularly novel and tells stories that are fairly well known; my interest is driven in […]

Maps of Philadelphia Churches, Part 1

U.S. Census data shows overall trends across the U.S., in the service of providing a broad view of national trends, from populations shifts to immigration. However, it is done every ten years, and can’t track everything. I thought it’d be interesting to make maps based on the locations of religious institutions – each these accounts […]

Visualizing Citations in U.S. Law

This visualization shows how frequently citations occur between sections of U.S. Law. Mouseover to focus on a particular Title. The thickness of the links between Titles encodes the frequency of citations between the sections, including self-citations. Since the names don’t fit in the chart, a full list of titles is included below and in a […]

U.S. Laws vs. The Human Genome

Since you can download the U.S. Code, I thought it would be interesting to compare the size to that of the Human Genome, operating on the premise that the latter represents the DNA for a living thing, and the former, the DNA for a nation. I’ve charted this below – to reproduce this you need […]

Visualizing Six Million Files and Folders

Each year there are nearly 300,000 of these in Federal Federal Civil Court, 1.3-1.6 million in Federal Bankruptcy Court, but this pales in comparison to state courts, which accept just over 100 million cases each year. Even a small extract of these takes up a fair amount of space: This is what a court docket […]

Optimizing WordPress Tag Pages

Normally I don’t like to write about “blogging,” but since website traffic generates some interesting data, it’s worth looking at it from a computer science perspective, to see the issues involved. By default, WordPress has two multi-valued fields associated with an article, “Categories” and “Tags.” Categories are treated as a closed, hierarchical set, and tags […]


Data Exploration in Javascript

Google Analytics has a nice screen which shows alerts for changes that appear interesting – basically any large increase or decrease in traffic from a particular source: With appropriate API hooks, this screen could be built for any application that models data in a dimensional fashion, e.g. that uses faceted navigation (like Amazon search), or […]


My First A/B Test… with Results

A/B testing gets a lot of attention on Hacker News,, and other forums, and appeals to me as a data analysis exercise. As a software engineer with a practical bent, I like the concept of data analysis techniques which produce useful results while treating a system as a black box. This stands in contrast […]


Lessons Learned from 0 to 40,000 Readers

Starting Out I started writing a little over a year ago, after finding “Technical Blogging” by Antonio Cangiano through Hacker News. Since then, a bit over 40,000 people have read articles I’ve written, not a huge number in the grand scheme of things, but enough to draw a few lessons. The more I write, the […]