Beta SF Neighborhoods

Often I've found myself somewhere familiar in San Francisco, thinking "is this technically Mission or Noe or Castro?" — or somewhere completely unfamiliar, thinking "I wonder what neighborhood this is".

So I made this thing. It's an iPhone app which tells you where in San Francisco you are. This is me, at home:

It doesn't show you a map, or tell you the history of the neighborhood, or link to Wikipedia, or provide droll stereotypes or give you vital stats like population or elevation or weather. It just tells you what neighborhood you're currently in—and how far you are from the closest adjacent neighborhood. That's it.

I say "iPhone app" and I mean that in the same sense that Steve Jobs did in 2007 when he announced that the iPhone would support third-party apps. It's a web page.

Add it as a bookmark to the home screen, though, and it's pretty app-like. It works like this

• determine current lat/long using the HTML5 Geolocation API;
• compare with Dave Schweisguth's SF neighborhood boundaries (thanks Dave!); and
• determine where you are, and where's closest.

It's barely even a beta; more of a steel thread. But hey, have at it: visit isaa.ch/sf on your iPhone, and add a bookmark to your home screen.

Some limitations, even within the admittedly narrow feature scope:

• you pretty much have to be in San Francisco for it to be of any use;
• if you're not in San Francisco then not only will it be no use but the distance calculation (which depends on a pretty rough and ready approximation from spherical to planar geometry) will become less accurate the further you are away; and
• error cases aren't handled terribly gracefully.

That said, I use it myself all the time and find it useful. Next steps are probably factoring the code into something sane and putting it on Github. Don't hold your breath.