这个代码是Mathematica4.2版本的，所以现在版本运行会出错。但是不知道具体哪里错了，希望dalao们指点一下。
代码如下：
(* runtime: 10 seconds, V is the potential energy *)
<< LinearAlgebra`Tridiagonal`; n = 55; dx = 1.0/(n - 1); hbar = m = 1; dt = 2m dx^2/hbar; a = I hbar/dt; b = hbar^2/(4 m dx^2); blist = Table[b, {n - 1}];
psi = Table[Module[{p = {x - 0.25, y - 0.5}}, Exp[I {100, 0}.p - p.p/(2 0.14^2)]], {y, 0, 1, dx}, {x, 0, 1, dx}];
V = Table[If[0.48 < x < 0.52 && ! (0.4 < y < 0.475 || 0.525 < y < 0.6), 10000, 0], {y, 0, 1, dx}, {x, 0, 1, dx}];
Do[psi = Table[TridiagonalSolve[blist, 2a - 2b - V[[All, j]]/2, blist, (2a + 2b + V[[All, j]]/2)psi[[All, j]] - b Table[psi[[i, Min[n, j + 1]]] + psi[[i, Max[1, j - 1]]], {i, 1, n}]], {j, 1, n}]; psi = Table[TridiagonalSolve[blist, 2a - 2b - V[[i,All]]/2, blist, (2a + 2b + V[[i, All]]/2)psi[[All, i]] - b Table[psi[[j, Min[n, i + 1]]] + psi[[j, Max[1, i - 1]]], {j, 1, n}]], {i, 1, n}]; Show[Graphics[RasterArray[Map[(x = Min[Abs[
#]^2, 1];Hue[Arg[#
]/(2Pi), Min[1, 2(1 - x)], Min[1, 2x]]) &, psi + V, {2}]], AspectRatio -> 1]], {40}];

<< LinearAlgebra`Tridiagonal`
TridiagonalSolve
以上两个东西现在的版本应该怎么改呢？

直接搜索帮助
Compatibility/tutorial/LinearAlgebra/Tridiagonal
会告诉你怎么升级的
Mathematica kernel's built-in sparse solver LinearSolve has replaced TridiagonalSolve as a faster solver of tridiagonal matrices.

嗯，我查到是用linearsolve，可是下面这句代码好长，不知道怎么改才对。 TridiagonalSolve[blist, 2a - 2b - V[[All, j]]/2, blist, (2a + 2b + V[[All, j]]/2)psi[[All, j]] - b Table[psi[[i, Min[n, j + 1]]] + psi[[i, Max[1, j - 1]]], {i, 1, n}]]

应该是要把前面三个矩阵合成一个，但是blist在定义的时候是n-1，合起来进行A.x==b的时候，系数矩阵A是n×n的矩阵，这就很矛盾