中文说明： 在经典龙格-库塔法的基础上，提出一种更高精度的变步长龙格-库塔法，能够根据误差大小对步长自动做出调整。我们对其进行了相关测试，并用matlab指令检验正确性，结果表明效果不错，能达到经典方法更好的结果。
English Description：
Based on the classical Runge Kutta method, a more accurate variable step Runge Kutta method is proposed, which can automatically adjust the step size according to the error size. We test it, and use Matlab instructions to verify the correctness, the results show that the effect is good, can achieve better results of the classical method.