Example of dissolving lat/lon points in different projection systems, using UK TTWA shape files

point_in_polygon_uk_ttwas.py

# Geometry, shapefiles and projections
import fiona
from shapely.geometry import shape
from shapely.geometry import Point
import pyproj

# Generate a function to create a UK East/North point from Lon/Lat
wgs84 = pyproj.Proj(init = 'epsg:4326')
ukgrid = pyproj.Proj(init = 'epsg:27700')
EnPoint = lambda lon, lat : Point(*pyproj.transform(wgs84, ukgrid, lon, lat))

# File containing lat lon points
df = pd.read_json('gtr_academic_private.json') 

# Open TTWA shapes
shp_filename = 'Travel_to_Work_Areas_December_2011_Full_Clipped_Boundaries_in_United_Kingdom.shp'
ttwa_counts = {}
with fiona.open(shp_filename) as ttwas:
    # Iterate through ttwas
    for ttwa in ttwas:
        id_ = ttwa['id'] # TTWA id
        if id_ not in ttwa_counts:
            ttwa_counts[id_] = 0
        # Iterate through table looking for lat/lon points in TTWA
        for _,row in df.iterrows():
            lat = row['lat']
            lon = row['lon']
            try:
                point = EnPoint(lon,lat)
            except:
                continue
            if not point.within(shape(ttwa['geometry'])):
                continue                
            ttwa_counts[id_] += 1