[halal]

I am trying to calculate the average particle position and velocity. This is the basic code I am using:

pdi = self.GetPolyDataInput()
pdo =  self.GetPolyDataOutput()
newPoints = vtk.vtkPoints()
numPoints = pdi.GetNumberOfPoints()

sumx=0
sumy=0
sumz=0
sumvx=0
sumvy=0
sumvz=0

for i in range(0, numPoints):
    coord = pdi.GetPoint(i)
    x, y, z = coord[:3]
    sumx = sumx+x
    sumy = sumy+y
    sumz = sumz+z
    vx = pdi.GetPointData().GetArray("v").GetValue(0)
    vy = pdi.GetPointData().GetArray("v").GetValue(1)
    vz = pdi.GetPointData().GetArray("v").GetValue(2)
    sumvx = sumvx+vx
    sumvy = sumvy+vy
    sumvz = sumvz+vz

avx=sumx/numPoints
avy=sumy/numPoints
avz=sumz/numPoints
avvx=sumvx/numPoints
avvy=sumvy/numPoints
avvz=sumvz/numPoints

newPoints.InsertPoint(0, avx, avy, avz)

pdo.SetPoints(newPoints)

but I don't know how to write the average velocity into the output. Could someone point me in the right direction? I've tried looking for similar topics but I am getting quite confused with the programmable filter and what commands to use for specific purposes. Is there a list of possible commands for the programmable filter? Thank you for your answer