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comparison python/storage.py @ 645:5ed2118c959d

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added function to count collisions in vissim
author Nicolas Saunier <nicolas.saunier@polymtl.ca>
date Mon, 13 Apr 2015 00:11:21 +0200
parents bfaa6b95dae2
children 6680a69d5bf3
comparison
equal deleted inserted replaced
644:e54751e71d61 645:5ed2118c959d
663 objects = {} # dictionary of objects index by their id 663 objects = {} # dictionary of objects index by their id
664 664
665 if usePandas: 665 if usePandas:
666 from pandas import read_csv 666 from pandas import read_csv
667 from numpy import min, max, round 667 from numpy import min, max, round
668 data = read_csv(filename, delimiter=';', skiprows=16) 668 data = read_csv(filename, delimiter=';', comment='*', header=0, skiprows = 1)
669 data['LANE'] = data['LANE\LINK\NO'].astype(str)+'_'+data['LANE\INDEX'].astype(str) 669 data['LANE'] = data['LANE\LINK\NO'].astype(str)+'_'+data['LANE\INDEX'].astype(str)
670 data['TIME'] = data['$VEHICLE:SIMSEC']*simulationStepsPerTimeUnit 670 data['TIME'] = data['$VEHICLE:SIMSEC']*simulationStepsPerTimeUnit
671 grouped = data.loc[:,['NO','TIME']].groupby(['NO'], as_index = False) 671 grouped = data.loc[:,['NO','TIME']].groupby(['NO'], as_index = False)
672 instants = grouped['TIME'].agg({'first': min, 'last': max}) 672 instants = grouped['TIME'].agg({'first': min, 'last': max})
673 if warmUpLastInstant is not None: 673 if warmUpLastInstant is not None:
702 objects[objNum].timeInterval.last = instant 702 objects[objNum].timeInterval.last = instant
703 objects[objNum].curvilinearPositions.addPositionSYL(s, y, lane) 703 objects[objNum].curvilinearPositions.addPositionSYL(s, y, lane)
704 line = readline(inputfile, '*$') 704 line = readline(inputfile, '*$')
705 705
706 return objects.values() 706 return objects.values()
707
708 def countCollisionsVissim(filename, collisionTimeDifference = 0.2):
709 '''Counts the number of collisions per lane in a VISSIM trajectory file
710
711 To distinguish between cars passing and collision,
712 one checks when the sign of the position difference inverts
713 (if the time are closer than collisionTimeDifference)'''
714 from pandas import read_csv, merge
715 data = read_csv(filename, delimiter=';', comment='*', header=0, skiprows = 1, usecols = ['LANE\LINK\NO', 'LANE\INDEX', '$VEHICLE:SIMSEC', 'NO', 'POS'])
716 merged = merge(data, data, how='inner', left_on=['LANE\LINK\NO', 'LANE\INDEX', '$VEHICLE:SIMSEC'], right_on=['LANE\LINK\NO', 'LANE\INDEX', '$VEHICLE:SIMSEC'], sort = False)
717 merged = merged[merged['NO_x']>merged['NO_y']]
718
719 nCollisions = 0
720 for name, group in merged.groupby(['LANE\LINK\NO', 'LANE\INDEX', 'NO_x', 'NO_y']):
721 diff = group['POS_x']-group['POS_y']
722 if len(diff) >= 2 and min(diff) < 0 and max(diff) > 0:
723 xidx = diff[diff < 0].argmax()
724 yidx = diff[diff > 0].argmin()
725 if abs(group.loc[xidx, '$VEHICLE:SIMSEC'] - group.loc[yidx, '$VEHICLE:SIMSEC']) <= collisionTimeDifference:
726 nCollisions += 1
727 return nCollisions
707 728
708 def loadTrajectoriesFromNgsimFile(filename, nObjects = -1, sequenceNum = -1): 729 def loadTrajectoriesFromNgsimFile(filename, nObjects = -1, sequenceNum = -1):
709 '''Reads data from the trajectory data provided by NGSIM project 730 '''Reads data from the trajectory data provided by NGSIM project
710 and returns the list of Feature objects''' 731 and returns the list of Feature objects'''
711 objects = [] 732 objects = []