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Be resilient to None cost estimation

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This commit is contained in:
Rafa de la Torre 2016-07-05 20:52:41 +02:00
parent 77cdc3d8ff
commit b78bd05754
1 changed files with 13 additions and 2 deletions
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15
server/lib/python/cartodb_services/cartodb_services/mapzen/isolines.py
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@ -1,4 +1,5 @@
from math import cos, sin, tan, sqrt, pi, radians, degrees, asin, atan2
import logging
class MapzenIsolines:
@ -27,6 +28,14 @@ class MapzenIsolines:
Array of {lon: x, lat: y} as a representation of the isoline
"""
def calculate_isochrone(self, origin, transport_mode, isorange):
# NOTE: not for production
#logging.basicConfig(level=logging.DEBUG, filename='/tmp/isolines.log')
logging.debug('origin = %s' % origin)
logging.debug('transport_mode = %s' % transport_mode)
logging.debug('isorange = %d' % isorange)
if transport_mode != 'walk':
# TODO move this restriction to the appropriate place
raise NotImplementedError('walk is the only supported mode for the moment')
@ -42,12 +51,14 @@ class MapzenIsolines:
location_estimates = [self._calculate_dest_location(origin, a, upper_rmax / 2.0) for a in angles]
# calculate the "actual" cost for each location estimate as first iteration
# NOTE: sometimes it cannot calculate the cost and returns None. Just assume isorange and stop the calculations there
resp = self._matrix_client.one_to_many([origin] + location_estimates, 'pedestrian')
costs = [c['time'] for c in resp['one_to_many'][0][1:]]
costs = [(c['time'] or isorange) for c in resp['one_to_many'][0][1:]]
#import pdb; pdb.set_trace()
# iterate to refine the first solution, if needed
for i in xrange(0, self.MAX_ITERS):
logging.debug('costs = %s' % costs)
errors = [(cost - isorange) / float(isorange) for cost in costs]
max_abs_error = max([abs(e) for e in errors])
if max_abs_error <= self.TOLERANCE:
@ -66,7 +77,7 @@ class MapzenIsolines:
# and check "actual" costs again
resp = self._matrix_client.one_to_many([origin] + location_estimates, 'pedestrian')
costs = [c['time'] for c in resp['one_to_many'][0][1:]]
costs = [(c['time'] or isorange) for c in resp['one_to_many'][0][1:]]
return location_estimates