diff --git a/src/batch_distance.py b/src/batch_distance.py new file mode 100755 index 0000000..8b5f687 --- /dev/null +++ b/src/batch_distance.py @@ -0,0 +1,99 @@ +# Batch_Distance.py: Batch process a bunch of distance measurements. + +import sys +import argparse +import csv +import json +import math +import configparser +import urllib.parse +import urllib.request + + +class GeocodingError(RuntimeError): + pass + + +def geocode_google(config, address): + apikey = config['google']['apikey'] + if not apikey: + raise GeocodingError("Google API key not specified") + query = { 'key': apikey, 'address': address, 'region': 'us'} + url = 'https://maps.googleapis.com/maps/api/geocode/json?' + \ + urllib.parse.urlencode(query, quote_via=urllib.parse.quote) + with urllib.request.urlopen(url) as response: + if response.status == 200: + apireturn = json.loads(response.read()) + stat = apireturn['status'] + if stat == 'OK': + results = apireturn['results'] + if len(results) > 1: + raise GeocodingError(f"Google API returned ambiguous results (total count {len(results)})") + coords = results[0]['geometry']['location'] + return coords['lat'], coords['lng'] + elif stat == 'ZERO_RESULTS': + return None + else: + raise GeocodingError(f"Google API returns status of {stat}") + else: + raise GeocodingError(f"Google API returns {response.status} HTTP status code") + + +OFFICE_LOCATION = (40.0187905, -105.2764775) # office location - 1433 Pearl Street, Boulder, CO +RADIUS = 6371.0 * 1000.0 # Earth radius in meters +METERS_PER_MILE = 1852.0 # number of meters per mile + + +def distance_miles(point1, point2): + Φ1 = math.radians(point1[0]) + Φ2 = math.radians(point2[0]) + ΔΦ = math.radians(point2[0] - point1[0]) + Δλ = math.radians(point2[1] - point1[1]) + a = math.sin(ΔΦ / 2.0) * math.sin(ΔΦ / 2.0) + math.cos(Φ1) * math.cos(Φ2) * math.sin(Δλ / 2.0) * math.sin(Δλ / 2.0) + c = 2 * math.atan2(math.sqrt(a), math.sqrt(1.0 - a)) + return RADIUS * c / METERS_PER_MILE + + +THRESHOLD_RADIUS = 15.0 # number of miles in "acceptable" threshold +ERROR_BAR_WIDTH = 0.5 # number of miles in "error bar" surrounding threshold + + +def classify_distance(dist): + if dist > (THRESHOLD_RADIUS + ERROR_BAR_WIDTH / 2): + return 'RED' + if dist >= (THRESHOLD_RADIUS - ERROR_BAR_WIDTH / 2): + return 'YELLOW' + return 'GREEN' + + +cmdline_parser = argparse.ArgumentParser() +cmdline_parser.add_argument('input', help='The input file containing locations to be checked.') +cmdline_parser.add_argument('output', nargs='?', help='The output file name that will receive the processed data.') +cmdline_parser.add_argument('-C', '--config', default='geoapi.ini', help='The geocoding API configuration file') + + +def main(args): + opts = cmdline_parser.parse_args(args) + config = configparser.ConfigParser() + config.read(opts.config) + output_name = opts.output + if not output_name: + output_name = opts.input + '.out' + with open(opts.input, newline='') as input_file: + dialect = csv.Sniffer().sniff(input_file.read(1024)) + input_file.seek(0) + reader = csv.reader(input_file, dialect) + with open(output_name, mode='w') as output_file: + writer = csv.writer(output_file, dialect) + for in_row in reader: + coords = geocode_google(config, in_row[1]) + if coords: + dist = distance_miles(OFFICE_LOCATION, coords) + out_row = [in_row[0], in_row[1], coords[0], coords[1], dist, classify_distance(dist)] + else: + out_row = [in_row[0], in_row[1], '*** Unable to locate'] + writer.writerow(out_row) + + +if __name__ == '__main__': + sys.exit(main(sys.argv[1:]))