def zoomTo(self, newFocalPoint, newPosition=None):

        self.interp = vtk.vtkCameraInterpolator()
        self.interp.AddCamera(0.0, self.getCameraCopy())

        c = self.getCameraCopy()
        newFocalPoint = np.array(newFocalPoint)
        oldFocalPoint = np.array(c.GetFocalPoint())
        oldPosition = np.array(c.GetPosition())

        if newPosition is None:
            if self.maintainViewDirection:
                newPosition = oldPosition + (newFocalPoint - oldFocalPoint)
            else:
                newPosition = oldPosition
            newPosition += self.positionZoom*(newPosition - newFocalPoint)
            #newPosition = newFocalPoint - self.positionZoom*(newFocalPoint - newPosition)

        c.SetFocalPoint(newFocalPoint)
        c.SetPosition(newPosition)
        c.SetViewUp([0.0, 0.0, 1.0])

        self.interp.AddCamera(1.0, c)
        self.startTime = time.time()
        self.start()
dataset/ETHPy150Open RobotLocomotion/director/src/python/director/cameracontrol.py/Flyer.zoomTo/swapped operands of `-`