Mathematica计算中心流形

gouxu

我按照天津大学张琪昌所著《分岔与混沌理论及应用》上给的程序算书上62页的例子4.4.1，
报错，程序所读取的文本文件center.txt必须和程序在同一目录下吗？

代码：
center.txt
[url=]\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\[/url]
centerdimension=1;
dx[1]=x[1] y[1];
dy[1]=-y[1]+arf*x[1]^2;
korder=5;
total=2;
[url=]\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\[/url]

[url=]\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\[/url]
ReadList["center.txt"]
remainder = total - centerdimension
aa = Table[a[i, j], {i, remainder}, {j, 2, korder}];
hx = Table[0, {remainder}];
Do[hx = Sum[a[i, j] x[1]^j, {j, 2, korder}] +
      O[x[1]]^(korder + 1), {i, 1, remainder}];
my = Table[0, {remainder}];
Do[y = hx[], {i, 1, remainder}];
Do[nx = D[hx[], x[1]] dx[1] - dy == 0; my[] = LogicalExpand[nx], {i,
        1, remainder}];
myok = Flatten[my];
aij1 = Flatten[aa];
my2 = Solve[myok, aij1];
my2 = Flatten[my2];
dx[1] = Simplify[dx[1] /. my2];
dx[1] = Normal[dx[1]];
centermaniford = {}
Do[dx[jj] = dx[jj];
  dx[jj] = Expand[dx[jj]];
  len = Length[dx[jj]];
  eff = Table[0, {len}];
  Do[item = dx[jj][];
    ee = 0; Do[eii = Exponent[item, x[ii]];
      ee = ee + eii;, {ii, 1, centerdimension}];
    If[ee > korder, eff[] = eff[], eff[] =
eff[] + item];, {i, 1, len}];
  dx[jj] = 0;
  len1 = Length[eff];
  Do[dx[jj] = dx[jj] + eff[];, {i, 1, len1}];
  centermaniford = Join[{dx[jj]}, centermaniford];, {jj, 1, centerdimension}]
centermaniford = Reverse[centermaniford]
centermaniford = Simplify[centermaniford]
[url=]\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\[/url]

报错：

yzsldj

这个程序已经讨论过，肯定是有问题的，最好能让《分岔与混沌理论及应用》的作者出来更正一下。

lushuang8

确实是这样的！