三个程序,分别以四阶龙格库塔法和欧拉法解洛伦兹方程,并绘制相图,时间演化图,庞加莱截面图.-Three procedures, respectively, fourth-order Runge-Kutta method and Euler method for solving the Lorentz equation and draw the phase diagram, the time evolution of the map, Poincare section.