tweetmap.py

#!/usr/bin/env python

import psycopg2 as pg
import Image
from sys import argv

conn = pg.connect(database='tweets', user='char', host='localhost')
cur = conn.cursor()

pxper = 16

# south = 37
# north = 45
# east = -67
# west = -80

south = 24
north = 50
east = -64
west = -130

width_deg = east - west
height_deg = north - south

width_px = width_deg * pxper
height_px = height_deg * pxper

print (width_px, height_px)

out = Image.new('RGB', (width_px, height_px))
o = out.load()

def scale(lat, lon):
  lat -= south
  lon -= west
  lat = height_px - int(lat * pxper)
  lon = int(lon * pxper)
  return lat, lon

def bump(n, rgb):
  rgb = list(rgb)
  rgb[n] += 80
  return tuple(rgb)

cur.execute('select lat, lon, text from tweets where lat > %s and lat < %s and lon > %s and lon < %s', (south, north, west, east))

for pt in cur:
  lat, lon = scale(pt[0], pt[1])
  if 'beach' in pt[2]: n = 0
  elif 'river' in pt[2]: n = 1
  elif 'bbq' in pt[2] or 'BBQ' in pt[2]: n = 2
  else: continue
  try:
    o[lon, lat] = bump(n, o[lon, lat])
  except IndexError:
    # Fenceposts:
    print lon, lat

out.save(argv[1])