我有一个python脚本,它调用OpenTripPlanner来计算成对的地理定位点之间的旅行时间矩阵。 python脚本使用for loop
计算每个出发时间的一个矩阵,并将其另存为单独的.csv
文件。
我想将此操作并行化以使其更快。虽然这项任务似乎令人尴尬地平行,但我几乎不知道Python
。根据我的阅读,我的预感是,最好的解决方案是使用multithreading
,将每个spt
保留在其中。
我真的很感激一些帮助。可以使用简单的可重现示例here。
这是python脚本:
#!/usr/bin/jython
from org.opentripplanner.scripting.api import OtpsEntryPoint
# Instantiate an OtpsEntryPoint
otp = OtpsEntryPoint.fromArgs(['--graphs', '.',
'--router', 'sto'])
# Start timing the code
import time
start_time = time.time()
# Get the default router
router = otp.getRouter('sto')
# Read Points of Destination - The file points.csv contains the columns GEOID, X and Y.
points = otp.loadCSVPopulation('centroids_sto.csv', 'Y', 'X')
dests = otp.loadCSVPopulation('centroids_sto.csv', 'Y', 'X')
for h in range(7, 19):
for m in range(0,60,30):
# Create a default request for a given time
req = otp.createRequest()
req.setDateTime(2015, 12, 28, h, m, 00)
req.setMaxTimeSec(3600) # 1h = 3600 seconds , 2h = 7200 seconds
req.setModes('WALK,TRANSIT,BUS,TRAM,RAIL,SUBWAY') # ("TRAM,RAIL,SUBWAY,FUNICULAR,GONDOLA,CABLE_CAR,BUS")
# Create a CSV output
matrixCsv = otp.createCSVOutput()
matrixCsv.setHeader([ 'mode', 'depart_time', 'origin', 'destination', 'walk_distance', 'travel_time' ]) # travel_time in seconds
# Start Loop
for origin in points:
print "Processing origin: ", str(h)+"-"+str(m)," ", origin.getStringData('idhex')
req.setOrigin(origin)
spt = router.plan(req)
if spt is None: continue
# Evaluate the SPT for all points
result = spt.eval(dests)
# Add a new row of result in the CSV output
for r in result:
matrixCsv.addRow([ 'public transport', str(h) + ":" + str(m) + ":00", origin.getStringData('idhex'), r.getIndividual().getStringData('idhex'), r.getWalkDistance() , r.getTime()])
# Save the result
matrixCsv.save('traveltime_matrix_sto_pt_'+ str(h)+"-"+str(m) + '.csv')
# Stop timing the code
print("Elapsed time was %g seconds" % (time.time() - start_time))