def getPoi(self) :
#---- Step 1 : Eliminate 0-weighted cell ------------------------------------------------------------#
for key in self.weights.keys() :
if (self.weights[key]["weight"]==0) : self.weights.pop(key, None)
#----------------------------------------------------------------------------------------------------#
keys=self.weights.keys()
indexes=np.array(keys)
positions=np.array([self.weights[key]["center"] for key in keys])
weights=np.array([self.weights[key]["weight"] for key in keys])
#---- Step 2 : Mode clustering of cells (meanshift) -------------------------------------------------#
data=np.array([[position.longitude(),position.latitude()] for position in positions])
ms = MeanShift(bandwidth=self.bandwidth,bin_seeding=True)
ms.fit(data)
labels = ms.labels_
cluster_centers = ms.cluster_centers_
labels_unique = np.unique(labels)
n_clusters_ = len(labels_unique) - (1 if -1 in labels else 0)
#----------------------------------------------------------------------------------------------------#
#---- Step 3 : Creating the list of Poi -------------------------------------------------------------#
self.poi=[]
infrequentVisits=[]
for k in range(n_clusters_) :
#center = cluster_centers[k]
my_members = labels == k
weightedPositions=zip(list(indexes[my_members]),list(positions[my_members]),list(weights[my_members]))
maximum=max(weightedPositions,key=lambda element : element[2])
poi=Poi(k,maximum[1].longitude(),maximum[1].latitude())
temporaryVisits=[]
for element in weightedPositions :
for visit in self.weights[tuple(element[0])]["visits"] :
temporaryVisits.append(visit)
temporaryVisits=sorted(temporaryVisits,key=lambda visit : visit.arrival)
visits=[temporaryVisits[0]]
for i in range(1,len(temporaryVisits)) :
lastVisit=visits[-1]
visit=temporaryVisits[i]
if (visit.arrival<=lastVisit.departure) :
lastVisit.departure=max(lastVisit.departure,visit.departure)
else : visits.append(visit)
if (len(visits)>=self.freqThres) :
poi.setVisits(visits)
self.poi.append(poi)
else : infrequentVisits.extend(visits)
if (infrequentVisits) : self.poi.append(Poi('I',float('nan'),float('nan'),sorted(infrequentVisits,key = lambda visit : visit.arrival)))
#----------------------------------------------------------------------------------------------------#
self.finalize(self.poi,mergeVisits=False)
return self.poi
def getPoi(self):
self.poi = []
# ---- Step 1 : Get events near to each stop point ---------------------------------------------------#
associatedVisits = []
neighboorsServerAll = NearestNeighbors(radius=self.distanceThres, algorithm="auto", leaf_size=10)
neighboorsServerAll.fit(np.array([event.position for event in self.events]))
for i in range(len(self.stops)):
associatedVisits.append(set(neighboorsServerAll.radius_neighbors(self.stops[i].position)[1][0]))
# ----------------------------------------------------------------------------------------------------#
# ---- Step 2 : Merge stop points onto poi and merge there visits ------------------------------------#
aggregatedPOI = np.array([-1] * len(self.stops))
numberOfPOI = 0
for i in range(len(self.stops)):
inIntersection = []
for j in range(len(self.stops)):
if associatedVisits[i] & associatedVisits[j]:
inIntersection.append(j)
poiId = min(aggregatedPOI[inIntersection])
if poiId == -1:
numberOfPOI += 1
poiId = numberOfPOI
aggregatedPOI[inIntersection] = poiId
listPoiandNeighboorsIndex = []
for poiId in set(aggregatedPOI):
members = self.stops[aggregatedPOI == poiId]
indices = np.array(range(len(self.stops)))[aggregatedPOI == poiId]
neighboors = set()
for i in indices:
neighboors |= associatedVisits[i]
poi = Poi(
poiId,
sum([p.longitude() for p in members]) / len(members),
sum([p.latitude() for p in members]) / len(members),
)
listPoiandNeighboorsIndex.append((poi, sorted(neighboors)))
# ----------------------------------------------------------------------------------------------------#
# ---- Step 3 : Creating the list of Poi -------------------------------------------------------------#
infrequentVisits = []
for item in listPoiandNeighboorsIndex:
poi, neighborsIndex = item
j = neighborsIndex[0]
for i in range(1, len(neighborsIndex)):
if neighborsIndex[i] > neighborsIndex[i - 1] + 1:
visit = Visit(-1, self.events[j].time, self.events[neighborsIndex[i - 1] + 1].time)
j = neighborsIndex[i]
if visit.duration() >= self.stayTimeThres:
poi.addVisit(visit)
k = neighborsIndex[-1] + 1 if (neighborsIndex[-1] + 1 < len(self.events)) else neighborsIndex[-1]
visit = Visit(-1, self.events[j].time, self.events[k].time)
if visit.duration() >= self.stayTimeThres:
poi.addVisit(visit)
if poi.visits:
if len(poi.visits) >= self.freqThres:
self.poi.append(poi)
else:
infrequentVisits.extend(poi.visits)
if infrequentVisits:
self.poi.append(
Poi("I", float("nan"), float("nan"), sorted(infrequentVisits, key=lambda visit: visit.arrival))
)
# ----------------------------------------------------------------------------------------------------#
self.finalize(self.poi, mergeVisits=False)
return self.poi
