def __calcInitialCentroids():
self.__centroidByEvent = {}
self.__centroids = []
def createCentroid(point):
centroid = Centroid()
centroid.addMember(point)
self.__centroidByEvent[point] = centroid
self.__centroids.append(centroid)
maxDist = 0
points = None
if len(self.__eventList)>1:
cursors = self.__eventList.getCursors()
for p in cursors:
for q in cursors:
dist = getDistSquared(p.getPos(),q.getPos())
if dist >= maxDist and p != q:
points = p,q
maxDist = dist
assert(points)
for point in points:
createCentroid(point)
elif len(self.__eventList) == 1:
createCentroid(self.__eventList.getCursors()[0])
def __calcMemberships (self):
""" returns True if a membership changed, else False."""
changed = False
if not len(self.__centroids):
return changed
for point in self.__eventList.getCursors():
closestCentroid = self.__centroids[0]
minDist = getDistSquared(point.getPos(), closestCentroid.getPos())
for centroid in self.__centroids:
distance = getDistSquared (point.getPos(), centroid.getPos())
if distance < minDist:
minDist = distance
closestCentroid = centroid
if not closestCentroid.hasMember(point):
self.__doNewMotion = True
if point in self.__centroidByEvent:
self.__centroidByEvent[point].removeMember(point)
self.__centroidByEvent[point] = closestCentroid
closestCentroid.addMember(point)
changed = True
return changed
