--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/busroute.py Wed Jul 29 23:45:53 2020 +0300
@@ -0,0 +1,130 @@
+#!/usr/bin/env python3
+def via_factor(region_name, *, regions):
+ # how important is it that
+ if region_name in regions:
+ return float(regions[region_name]['via_factor'])
+ else:
+ return 0
+
+def simplify_name(region_name, *, regions, replace = False):
+ # take short_name to account
+ region = regions.get(region_name)
+ if region:
+ return region.get('short_name', region_name)
+ else:
+ return region_name
+
+def destinations_list(
+ itinerary,
+ *, trip_length,
+ regions,
+ whole = False,
+ format = 'medium',
+):
+ '''
+ Produces a sign of destinations for the given itinerary.
+ `itinerary`: list of region names passed through
+ `trip_length`: length of the itinerary in meters.
+ `regions`: the regions table, used to decide what is important to show.
+ `whole`: whether or not the starting place is also included.
+ `format` controls what kind of sign to produce:
+ - 'short': at most 2 destinations, with reducing
+ - 'medium': at most 3 destinations, with reducing
+ - 'long': at most 4 destinations, no reducing.
+ Returns a list of region names.
+ e.g. ['Turun keskusta', 'Ihala', 'Kauppakeskus Mylly']
+ for Föli bus route 220 at the student village.
+ '''
+ # prefer longer destination signs on longer routes
+ length = ((trip_length / 600) * 3 + len(itinerary) * 2) / 5
+ # collect regions along the itinerary
+ have_already = set()
+ i = 0
+ if not itinerary:
+ # not going anywhere?
+ return ''
+ while i < len(itinerary):
+ region = regions.get(itinerary[i])
+ if not itinerary[i] or itinerary[i] in have_already:
+ del itinerary[i]
+ else:
+ have_already.add(itinerary[i])
+ i += 1
+ from_place = itinerary[0]
+ destination = itinerary[-1]
+ route_weights = {}
+ # create weights for all places along the way. Transforming by x^-0.3
+ # lessens weights for places further out in the itinerary.
+ f = lambda i: i**-0.3
+ # this factor scales the weights so that they become comparable against
+ # constant values
+ factor = 1 / max(f(i + 1) for i in range(len(itinerary)))
+ while via_factor(itinerary[-1], regions = regions) < 0:
+ del itinerary[-1]
+ if not itinerary:
+ return ''
+ destination = itinerary[-1]
+ for i, stop in enumerate(itinerary):
+ # transform index by:
+ # - our gradually decreasing x^-0.3 curve,
+ # - our normalising factor,
+ # - and the via_factor of the stop
+ route_weights[stop] = f(i + 1) * factor * via_factor(stop, regions = regions)
+ # ensure that the starting region does not make it into the destinations
+ # sign by setting its weight to 0
+ if from_place in route_weights:
+ route_weights[from_place] = 0
+ # ensure that the destination does make it to the signpost
+ route_weights[destination] = 1.0e+10
+ # sort destinations by importance
+ weights = sorted(
+ [
+ (stop, route_weights[stop], i)
+ for i, stop in enumerate(itinerary)
+ if route_weights[stop] >= 1
+ ], key = lambda stop: -stop[1])
+ # now consider what do we want to display:
+ if format == 'long':
+ # long format, just take at most four destinations
+ weights = weights[:4]
+ elif format == 'short':
+ # short format, take at most two destinations
+ weights = weights[:2]
+ # possibly drop the via-region as well
+ try:
+ if weights[1][0] != destination and weights[1][1] < (500 / length ** 1.15):
+ del weights[1]
+ except IndexError:
+ pass
+ elif format == 'medium':
+ # regular format, at most three destinations
+ weights = weights[:3]
+ # if the third sign value is not significant enough, drop it
+ try:
+ if weights[2][0] != destination and weights[2][1] < (725 / length ** 0.8):
+ del weights[2]
+ except IndexError:
+ pass
+ # and repeat for the second sign value
+ try:
+ if weights[1][0] != destination and weights[1][1] < (500 / length ** 1.15):
+ del weights[1]
+ except IndexError:
+ pass
+ else:
+ raise ValueError(str.format('Unknown format {format}', format = repr(format)))
+ # restore the signpost back to itinerary order
+ weights.sort(key = lambda weight_data: weight_data[2])
+ # form the sign
+ sign = [paino[0] for paino in weights]
+ old_sign = sign.copy()
+ sign = []
+ for place in old_sign:
+ if place not in sign:
+ sign.append(place)
+ if whole:
+ # whole format, also include the starting point
+ sign = [from_place] + sign
+ if not sign:
+ sign = [destination]
+ return sign