求教一个微分方程组作图的问题

lyxxl

从一篇论文上看的一个吸引子图,百思不得其解,不知道论文作者是怎么画的,能不能请高人指点一下，只要给我点拨一下怎么做就好,多谢了!
无量纲化以后的方程是这样的:
不明白的是这段文字：
Since the system （4）–（7） describing the particle dynamics
is a periodically forced system, it is natural to consider the
stroboscopic section defined by the time-T map of the flow,
where T is the period of the flow. We denote this map by F.
It is easy to check that if （Y1(t)；Y2(t)；V1(t)；V2(t)）
is a solution of Eqs. （4）–（7）, then
（Y1(t)＋2n；Y2(t)+2m；V1(t)；V2(t)）;
（Y1(t)＋1；Y2(t)+1；V1(t)；V2(t)）;
（-Y1(t)＋2；Y2(t)；-V1(t)；V2(t)）;
（-Y1(t)＋1；Y2(t)+1；-V1(t)；V2(t)）;
are also solutions, where m,n are integers. After identifying
all these points with （Y1(t)；Y2(t)；V1(t)；V2(t)）, the mapping
F can be regarded as being defined on E=
［0,1］＊［0,1］＊R＊R;   R＊R are the velocity components!. We
denote this mapping by F' , in order to distinguish it from F
defined on the whole phase space. In fact, the original dynamics
represented by Eqs. (4)–(7) can also be defined on E,
Then, F'is the time-T mapping of this flow restricted
to E.
Figure 1 shows the projection onto the configuration
space of the chaotic attractor for the mapping F˜ with the
parameter values A=3.2, W=0.8, R=1, k=2.72, omiga=pi
(this means that the forcing period is T=2)
我的问题是：
time-T map怎么画？是画频闪图吗？
如何能画出如下图的吸引子来，虽然无量纲化了Ｙ１，Ｙ２，但求解完之后的Ｙ１，Ｙ２都是大于１的，他这图到底是什么意思啊？
请各位前辈不吝赐教，如有热心的前辈请留下邮箱，我可把全文发过去请教！
多谢了！

gghhjj

time-T map怎么画？是画频闪图吗？
如何能画出如下图的吸引子来，虽然无量纲化了Ｙ１，Ｙ２，但求解完之后的Ｙ１，Ｙ２都是大于１的，他这图到底是什么意思啊？
请各位前辈不吝赐教，如有热心的前辈请留下邮箱，我可把全文发过去请教！
多谢了！

time-T map应该就是闪频图

无量纲化未必是到1吧，没仔细看