三阶龙格库塔法的计算公式为： 三阶龙格库塔公式的Matlab程序代码：function y = DELGKT3_kuta(f, h,a,b,y0,varvec)format long;N = (b-a)/h;y = zeros(N+1,1);y(1) = y0;x = a:h:b;var = findsym(f);for i=2:N+1 K1 = Funval(f,varvec,x(i-1) y(i-1); K2 = Funval(f,varvec,x(i-1)+h/2 y(i-1)+K1*h/2); K3 = Funval(f,varvec,x(i-1)+h y(i-1)-h*K1+K2*2*h); y(i) = y(i-1)+h*(K1+4*K2+K3)/6;endformat short;DELGKT3_kuta函数运行时需要调用下列函数： function fv=Funval(f, varvec, varval) var= finds
