16 May 2012
Honey from Huffman trees
Did you know that NYC Open Data includes latitude/longitude for every tree in NYC? A tree census - amazing! Surely there's something fun we can do with that!
Well, bees in NYC do a lot of their nectar foraging from flowering trees. It could be interesting to see which kinds of trees my bees are likely foraging from. Bees can fly startlingly long distances to forage if they have to, but my sense is that a 2 mile radius is a decent rough estimate for how far they're likely to fly in search of nectar barring a barren neighborhood. Sure, there are plenty of other flowering plants in the city (I can certainly taste the clover in my spring honey, for instance), but it's still interesting to see which trees are likely contributing to the honey I harvest locally.
So, I pulled the tree census data into mysql to play with. (Bread crumbs for the inspired: I wanted to deploy on Dreamhost, so I used an old version of mysql and was stuck with mbrcontains narrowed down with the haversine equation (and cosine approximation, of course) to find only those trees actually within an n-mile radius of my starting point. Postgres and stcontains with a polygon approximation of the circle would be better, really.)
I'm displaying results as a Huffman tree - a visual representation of the data structure you create when you use Huffman encoding.
Visualized with D3.js, with leaf sizes proportional to the percentage of trees found of each type, it looks rather like this:
You can put in your own beehive address (or home, or neighborhood you're thinking of moving to, whatever makes you happy) and play with my tree-finder here.
When a thing is as dorky as it can possibly be, I know it is done right.
