def getInitialPoints(allPoints):
pointLen = len(allPoints)
resAllPoints = []
i = 0
prePoint = allPoints[i]
while i < pointLen:
curList = allPoints[i].strip('\n').split(',') # 去掉后面换行
curTuple = (curList[0], curList[1], curList[2], curList[3])
if i == 0:
curTuple = curTuple + (0, 0, 0, 'none', 0)
resAllPoints.append(curTuple)
pre = curTuple
i = i + 1
continue
if i == 1:
# 计算 速度、距离
distance = func.getDistance(float(pre[0]), float(pre[1]),
float(curList[0]), float(curList[1]))
timeInterval = func.getTimeInterval(pre[2], curList[2])
v = distance / timeInterval
curTuple = curTuple + (v, 0, distance, 'none', 0)
resAllPoints.append(curTuple)
pre = curTuple
# print(curTuple)
i = i + 1
continue
# 第3个点之后，计算速度、加速度、距离、point label
distance = func.getDistance(float(pre[0]), float(pre[1]),
float(curList[0]), float(curList[1]))
timeInterval = func.getTimeInterval(pre[2], curList[2])
v = distance / timeInterval
a = abs(v - pre[4]) / timeInterval
pointLabel = 'non-walk-point'
if v < vThreshold and a < aThreshold:
pointLabel = 'walk-point'
if i == pointLen - 1:
curTuple = curTuple + (v, a, distance, pointLabel, 0)
else:
curTuple = curTuple + (v, a, distance, pointLabel, 0)
resAllPoints.append(curTuple)
pre = curTuple
# print(curTuple)
i = i + 1
return resAllPoints
def addAccLabel(DBPath, i):
"""
add accelemeter and point_label (such as walk-point or non-walk-point)
for every GPS point.
-1 default there is no value (begin of the trajectory)
"none" default there is no value (begin of the tajectory)
"""
conn = DBUtil.get_conn(DBPath)
# find all points
fetchAllPointSql = 'select id, time_stamp, velocity from GPS_points_' + \
str(i)
allPointRecords = DBUtil.fetchAll(conn, fetchAllPointSql)
if allPointRecords is None:
print('fetch point set Fail!')
return
"""
allPointRecords contents:
[(id, time_stamp, velocity)]
[(1, '2008/04/30 21:48:31', 4.285027485451),...]
parameters contents:
[(accelermeter, point_label, id)]
"""
parameters = []
# default pre[2] = -1, means the first GPS point's valocity is -1
pre = allPointRecords[0]
for index in range(len(allPointRecords)):
cur = allPointRecords[index]
# print('point id: ' + str(cur[0]))
if cur[2] == -1:
parameters.append((-1, 'none', cur[0]))
pre = cur
continue
# pre = -1 and cur != -1
if pre[2] == -1:
parameters.append((-1, 'none', cur[0]))
pre = cur
continue
timeInterval = func.getTimeInterval(pre[1], cur[1])
# if pre time equals cur time, we set timeInterval 1 second
if timeInterval == 0:
timeInterval = 1
acc = abs(cur[2] - pre[2]) / timeInterval
pointLabel = 'non-walk-point'
if cur[2] < vThreshold and acc < aThreshold:
pointLabel = 'walk-point'
parameters.append((acc, pointLabel, cur[0]))
pre = cur
# print(parameters)
# update in the database
updateSql = 'update GPS_points_' + \
str(i) + ' set accelerometer = ?, point_label = ? where id = ?'
DBUtil.update(conn, updateSql, parameters)
DBUtil.closeDB(conn)
def addDistVelocity(DBPath, i):
"""
if time interval between cur and pre record is greater than 20min,
then we consider the begin of another trajectory, the first record's
distance and velocity of trajectory is -1 default.
we can say value "-1" can understand as the begin of single trajectory
"""
conn = DBUtil.get_conn(DBPath)
# find all points
fetchAllPointSql = 'select * from GPS_points_' + str(i)
allPointRecords = DBUtil.fetchAll(conn, fetchAllPointSql)
if allPointRecords is None:
print('fetch point set Fail!')
return
"""
records: type list-> [(1, 3, 39.9752333333333, 116.330066666667,
'2008/04/29 17:15:24', -1, -1, -1, 'non', 0, 0, 0, 0, 'none')......]
the index of time is 4
lat: 2 lon: 3
distance: 7
velocity: 5
"""
pre = allPointRecords[0]
# print(preRecord)
parameters = []
for index in range(len(allPointRecords)):
cur = allPointRecords[index]
if index == 0:
parameters.append((-1, -1, cur[0]))
continue
timeInterval = func.getTimeInterval(pre[4], cur[4])
# if pre time equals cur time, we set timeInterval 1 second
if timeInterval == 0:
timeInterval = 1
if timeInterval >= TimeThreshold:
parameters.append((-1, -1, cur[0]))
pre = cur
continue
# print("points id: " + str(cur[0]))
dist = func.getDistance(pre[2], pre[3], cur[2], cur[3])
lineTuple = (dist, dist / timeInterval, cur[0])
parameters.append(lineTuple)
pre = cur
updateSql = 'update GPS_points_' + \
str(i) + ' set distance = ?, velocity = ? where id = ?'
DBUtil.update(conn, updateSql, parameters)
DBUtil.closeDB(conn)
print("update distance and velocity successfully!")
def addTrueCP(DBPath, i):
"""
if the distance between an normal GPS points and actual
transition points is within 150 m, we regard the GPS point
is transition point.
"""
conn = DBUtil.get_conn(DBPath)
# find all points
fetchAllPointSql = 'select id,lat,lon,accelerometer,mode,time_stamp ' + \
'from GPS_points_' + str(i)
allPointRecords = DBUtil.fetchAll(conn, fetchAllPointSql)
if allPointRecords is None:
print('fetch point set Fail!')
return
"""
records: type list-> [(1, 39.9752333333333, 116.330066666667, 'none').....]
id: 0
lat: 1
lon: 2
accelerometer: 3
mode: 4
time_stamp: 5
"""
parameters = []
recordLen = len(allPointRecords)
pre = allPointRecords[0]
index = 1
while index < recordLen:
cur = allPointRecords[index]
if cur[3] == -1:
pre = cur
index += 1
continue
tempTime = func.getTimeInterval(pre[5], cur[5])
if cur[4] != pre[4] and tempTime < TimeThreshold:
parameters.append((cur[0], ))
# forward
forStart = index - 1
while forStart >= 0:
forward = allPointRecords[forStart]
tempDist = func.getDistance(cur[1], cur[2], forward[1],
forward[2])
if tempDist > transiPointDist:
break
parameters.append((forward[0], ))
forStart -= 1
# afterward
aftStart = index + 1
while aftStart < recordLen:
aftward = allPointRecords[aftStart]
tempDist = func.getDistance(cur[1], cur[2], aftward[1],
aftward[2])
if tempDist > transiPointDist:
break
parameters.append((aftward[0], ))
aftStart += 1
# update into database
if len(parameters) != 0:
print(parameters)
updateSql = "update GPS_points_" + str(i) + \
" set is_true_tp = 1 where id = ?"
DBUtil.update(conn, updateSql, parameters)
parameters.clear()
pre = cur
index += 1
DBUtil.closeDB(conn)
def addStayPoint(DBPath, i):
"""
caculate stay point value in table GPS_points_i,
value: 1 denotes the point is stay point
value: 0 denotes the normal stap point
step 1: find stay point according to rule:
Distance(p1, p2)<D and TimeDiff(p1, p2)>T
step 2: use direction change to drop extra stay points
step 3: noise filtering
"""
conn = DBUtil.get_conn(DBPath)
# find all points
fetchAllPointSql = 'select * from GPS_points_' + str(i)
allPointRecords = DBUtil.fetchAll(conn, fetchAllPointSql)
if allPointRecords is None:
print('fetch point set Fail!')
return
"""
records: type list-> [(1, 3, 39.9752333333333, 116.330066666667,
'2008/04/29 17:15:24', -1, -1, -1, 'non', 0, 0, 0, 0, 'none')......]
id: 0
time: 4
lat: 2
lon: 3
distance: 7
velocity: 5
"""
parameters = []
stayPointSet = []
recordLen = len(allPointRecords)
index = 0
while index < recordLen:
cur = allPointRecords[index]
j = index + 1
token = 0
while j < recordLen:
aft = allPointRecords[j]
# if another trajectory bagins
if aft[7] == -1:
index = j
token = 1
break
dist = func.getDistance(cur[2], cur[3], aft[2], aft[3])
if dist > StayPoinDistThd:
curTimeDiff = func.getTimeInterval(cur[4], aft[4])
if curTimeDiff > StayPoinTiThd:
# index ~ j points are added to stayPointSet
sIndex = index
while sIndex < j:
temp = allPointRecords[sIndex]
stayPointSet.append((temp[0], temp[2], temp[3]))
sIndex += 1
# output the stay points set
# print(stayPointSet)
"""
check stay points set 1,
abandon the case of traffic congestion
"""
# isTraCong = func.isTrafficCongestion(stayPointSet,
# changeAngle,
# changeRate)
# if isTraCong == 1:
# stayPointSet.clear()
# break
"""
check stay points set 2 (noise filtering),
get content:
[(39, 39.8146666666667, 119.476816666667, 0),......],
"""
resPointList = func.noiseFilter(stayPointSet, 3)
"""
insert stay points into table GPS_points_i
field: is_stay_point
"""
for item in resPointList:
parameters.append((item[3], item[0]))
# print("resPointList's size:" + str(len(resPointList)))
# print(resPointList)
func.writeFile(
'stay_point_set_result.txt',
"resPointList's size: " + str(len(resPointList)))
func.writeFile('stay_point_set_result.txt',
str(resPointList))
func.writeFile('stay_point_set_result.txt', "\n\n")
updateSql = "update GPS_points_" + str(i) + \
" set is_stay_point = 1, is_deleted = ? where id = ?"
# DBUtil.update(conn, updateSql, parameters)
# clear the stay points set
resPointList.clear()
stayPointSet.clear()
parameters.clear()
index = j
token = 1
break
else:
break
j += 1 # end while
if token != 1:
index += 1
DBUtil.closeDB(conn)