代码:
function soleqns2
%EDIT BY PSL@CSU
%QQ：547423688
%Email：[email protected]
y0=[1 0 0 0];
[x,num_y]=ode45(@eqns2,[0,20],y0);
plot(x,num_y(:,1));
function du=eqns2(x,u)
du=zeros(4,1);
du(1)=u(2);
du(2)=u(3);
du(3)=u(4);
du(4)=u(4)+1;
%EDIT BY PSL@CSU
%QQ：547423688
%Email：[email protected]