1 用途：4阶经典龙格库塔格式解常微分方程y =f(x, y), y(x0)=y0

格式：[x, y]=marunge4(dyfun,xspan,y0,h) dyfun为函数f(x,y),

xspan为求解区间[x0, xn], y0为初值, h为步长, x返回节点, y返回数值解



2 用途：用LU分解法解方程组Ax=b

-1　Uses: 4-order classical Runge-Kutta solution of ordinary differential equation form y ' = f (x, y), y (x0) = y0　Format: [x, y] = marunge4 (dyfun, xspan, y0, h ) dyfun for the function f (x, y),　xspan for solving the interval [x0, xn], y0 as the initial value, h the step size, x return to the node, y return to numerical solution of 2　Usage: solving equations using LU decomposition Groups of Ax = b