plot 轨迹图 只有一个点

baofeng

这是我的运行程序，想要画出一个轨迹图，x(5)和x(7)分别是横、纵方向上的位移。“chen”是计算程序，文件里内容比较繁冗，我将它作为附件给出（因为贴出来之后实在没法看）。
global w
w=200;
%x0=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
x0=[0.01,-0.01,0.0001,-0.00001,0.01,-0.01,0.0001,-0.00001,0.01,-0.01,0.0001,-0.00001,0.01,-0.01,0.0001,-0.00001,0.01,-0.01,0.0001,-0.00001,0.01,-0.01,0.0001,-0.00001,0.01,-0.01,0.0001,-0.00001,0.01,-0.01,0.0001,-0.00001];
tt=1000*2*pi/w;
[t,x]=ode45('chen',[0:tt/200:400*tt],x0);
plot(x(:,5),x(:,7));
hold on;
我的问题就是运行上面的程序之后，无法绘出曲线，最后给出的图像里就是一个点。请各位达人施以援手，谢谢。

[ 本帖最后由 sigma665 于 2008-5-28 14:22 编辑 ]

sigma665

没有出现你说的问题
不过数量级好大

咕噜噜

发散了，查找一下原因吧

baofeng

方程发散一般是什么原因呢？遇到过这种情况吗？

咕噜噜

两种情况，1、系统刚性2、初始条件不正确