铅垂平面飞行弹道仿真 名字为trajectory的是主程序。interp是一维、二维的插值程序，rk是龙格库它函数，grk2f是方程组的右端函数 -vertical plane flight trajectory simulation to name the trajectory of the main program. Interp is one-dimensional, two-dimensional interpolation procedures rk is Runge for it