Month: February 2014

Publicly Available Datasets

Sometimes learning to use data systems like MySQL means you need to get your hands on various publicly available sets of data. Here are some sources. Pro Publica, the investigative news powerhouse, has a Data Store. It’s mostly health care related material. Not all their datasets are free, but some are. If you’re interested in historical meteorological observations (weather data),… Read more →

Instagram the new Kodak? WhatsApp the new Ma Bell? Really?

Instagram is the new Kodak! So say respected public thinkers and pundits. A fifteen-person company has rubbed out a 147,000-person company. It’s the end of honest work and middle-class life. We’ll be all sitting in coffee shops delightedly sending selfies to each other. Now Facebook is sinking tens of gigadollars into a 70-person company called WhatsApp. The argument goes that… Read more →

The Vincenty great-circle distance formula

This Vincenty formula is a more numerically stable version of the spherical cosine law formula (commonly and wrongly known as the Haversine formula) for computing great circle distances. The question of numerical stability comes up specifically when the distances between points are small. In those cases the cosine is very close to 1, so the inverse cosine function is not… Read more →

New emailer services

Here are a couple of emailer services. https://madmimi.com/ This one needs investigating. http://mandrill.com/ This provides an API, and a WordPress plugin called wpmandrill. It’s a freemium service allowing up to 12K messages per month unpaid. It integrates nicely with WordPress, and provides pretty good SPF and DKIM email-authentication support. Read more →