fixed-point motion

例句：

1. 1. The motion of the planets is fixed-point motion.
   行星的运动是定点运动。
2. 2. In this model, the fixed-point motion is used to simulate the behavior of the system.
   在这个模型中，定点运动被用来模拟系统的行为。
3. 3. The researcher found that the fixed-point motion could be used to predict the future trends of the market.
   研究者发现，定点运动可以用来预测市场的未来趋势。