code: def compute(self, xt1, yt1, xt, yt, theta1t1, theta2t1, theta1, theta2):
      
      dx = xt - xt1
      dy = yt - yt1
  
      if self.numPoints < self.maxPoints:
        self.dxValues[self.numPoints,0] = dx
        self.dxValues[self.numPoints,1] = dy
  
        self.thetaValues[self.numPoints,0] = theta1
        self.thetaValues[self.numPoints,1] = theta2
  
        self.numPoints += 1
  
        # print >>sys.stderr, "Xt's: ", xt1, yt1, xt, yt, "Delta's: ", dx, dy
        # print >>sys.stderr, "Theta t-1: ", theta1t1, theta2t1, "t:",theta1, theta2
  
      elif self.numPoints == self.maxPoints:
        print >> sys.stderr,"Max points exceeded, analyzing ",self.maxPoints,"points only"
        self.numPoints += 1
docs: Accumulate the various inputs.