def update(self):

        newTargetPosition = self.getTargetPosition()

        delta = self.lastTargetPosition - newTargetPosition

        followAxes = [True, True, True]
        for i in xrange(3):
            if not followAxes[i]:
                delta[i] = 0.0

        self.lastTargetPosition = newTargetPosition

        c = self.camera

        oldFocalPoint = np.array(c.GetFocalPoint())
        oldPosition = np.array(c.GetPosition())

        c.SetFocalPoint(oldFocalPoint + delta)
        c.SetPosition(oldPosition + delta)
        self.view.render()
dataset/ETHPy150Open RobotLocomotion/director/src/python/director/cameracontrol.py/PositionTracker.update/swapped operands of `-`