[讨论]高斯消去法---这是用VB编的

god

Private Sub gauss_Click() '高斯消去法
. M, D5 [! E* m; {7 A9 w  F5 PDim n As Integer, i As Integer, j As Integer, a() As Single, s As String, l() As Single
i = 1: j = 1
; z; n) O4 n2 V0 h' Vn = Val(InputBox("请输入矩阵的阶数(即：方程组未知数个数)N", "方程的未知数个数n", 3))
/ v; b3 M- F  ]# Q* Q* J+ nReDim Preserve a(1 To n, 1 To n + 1)
ReDim Preserve l(1 To n, 1 To n + 1)
* P5 I" ?- P/ t$ N# C* `. B* ^Dim k As Integer, D As Single, m As Single, x() As Single, t As Single, a2() As Single
- Q. f; B: q, K% p0 oReDim Preserve a2(1 To n, 1 To n + 1) '为方便求Ax-b而设的a()
5 a6 U( G4 Z2 Y* `% \/ B8 MFor i = 1 To n
For j = 1 To n
a2(i, j) = a(i, j)
6 Y: S5 M- s/ @3 qNext
Next '将a()的值全部赋给a2()
. f" U) w1 M% [. Em = 0
D = 1
ReDim x(1 To n)
Print "--------------------------------"
Print "您输入的增广矩阵如下："
For i = 1 To n
$ y! f5 T; c1 V; h# X1 Rs = Trim(InputBox("请输入增广矩阵的第" & i & "行" + vbCrLf + "各元素之间请用空格分开", i & "行矩阵的输入"))
For j = 1 To n
6 i: ^* _$ R& Z6 ma(i, j) = Val(Left(s, InStr(s, " ")))
4 V  o3 C& B, }' m" |. Qs = Trim(Right(s, (Len(s) - InStr(s, " "))))
& R) }4 p' S0 @& u2 m2 dPrint a(i, j);
Next
a(i, n + 1) = Val(s)
3 e: b8 z, ?% ?6 F8 aPrint a(i, n + 1);
Print
Next
8 [3 A; q1 `1 J& V
For k = 1 To n - 1 '开始消元
: t  n9 K2 ]* MIf a(k, k) = 0 Then
/ m* Y* }9 t; K$ x1 uMsgBox " Sorry！解不出！" + vbCrLf + "原因是：a(" & k & "，" & k & ")=0了！", vbExclamation, "解不出呀！"
4 G1 c: v; f( d) [Exit Sub
8 u9 G0 Y$ ~5 q( gElse
For i = k + 1 To n
+ ?/ l" U* f  }l(i, k) = a(i, k) / a(k, k)
For j = k + 1 To n + 1
a(i, j) = a(i, j) - l(i, k) * a(k, j)
+ H) ~) I1 b0 x. JNext
) s* h- b/ h* NNext
5 X/ ~6 V$ ]; C5 v% D6 c* O& WD = D * a(k, k)
End If
Next k '消元结束
If a(n, n) = 0 Then
0 Y0 I7 w& u# J3 S3 zMsgBox "Sorry！“高斯法”对此矩阵无能为力！" + vbCrLf + "原因是：a(n.n)=0了", vbExclamation, "解不出呀！"
Exit Sub
9 F2 D) \1 }! SElse
D = D * a(n, n)
' j7 N# f0 @/ c+ d# O1 r% nEnd If
/ l* D" O' D. \; r/ F6 W" `Print "--------------------------------"
Print "系数行列式的值是："; D
4 |0 Y" `/ P9 l" mx(n) = a(n, n + 1) / a(n, n)
For k = n - 1 To 1 Step -1 '开始回代
+ y/ s& G% r- b) AFor j = k + 1 To n
0 l. `$ k5 z2 r- f# I8 c- um = m + a(k, j) * x(j)
Next j
x(k) = (a(k, n + 1) - m) / a(k, k)
7 C( h6 F7 q8 q7 Wm = 0
Next k '结束回代
) X, W8 p* [4 A" ?' O8 U/ H
5 v# e( s! V0 f7 z/ KPrint "--------------------------------"
Print "方程组的解如下："
3 A7 P% I0 a) u7 ~
2 Z1 |8 |) k1 o9 J& g6 [' V  i/ NFor k = 1 To n
Print
Print "X(" & k & ") = " & x(k)
Next k
Print "--------------------------------"
Print "其中各行Ax-b="
) h3 Q+ A. y) x# Z3 X) d! o( f+ aPrint
3 K! W* d8 M' ^- v0 L4 `/ e7 `For i = 1 To n
t = 0
For j = 1 To n
t = t + a2(i, j) * x(j)
Next j
t = t - a2(i, n + 1)
Print Spc(5); "第" & i & "行："; t
Print
Next i

/ Q& U- B/ Q7 ~9 v7 w3 eEnd SubPrivate Sub gauss_Click() '高斯消去法
$ c( M6 S9 Z) `4 T+ z( D. Z- S' QDim n As Integer, i As Integer, j As Integer, a() As Single, s As String, l() As Single
/ c0 w! q( J3 F9 q0 Vi = 1: j = 1
0 f+ t# u3 ^5 W$ _/ o: Y* x; E- T" on = Val(InputBox("请输入矩阵的阶数(即：方程组未知数个数)N", "方程的未知数个数n", 3))
( ^* o; W5 p5 L2 f; ~: p& p9 [2 x7 wReDim Preserve a(1 To n, 1 To n + 1)
ReDim Preserve l(1 To n, 1 To n + 1)
Dim k As Integer, D As Single, m As Single, x() As Single, t As Single, a2() As Single
) }. D* [/ D: j2 r2 WReDim Preserve a2(1 To n, 1 To n + 1) '为方便求Ax-b而设的a()
% K# Q9 n: X) t. |9 t) t" N3 lFor i = 1 To n
3 S  t, B* H! g, C2 y- VFor j = 1 To n
a2(i, j) = a(i, j)
Next
$ b6 n0 p$ O  i; v2 l  K9 cNext '将a()的值全部赋给a2()
m = 0
D = 1
9 D; W4 ]! O* ^. T! O! P* QReDim x(1 To n)
' O- c) X( G0 V+ kPrint "--------------------------------"
0 q. [+ w$ c- n3 u, g6 k: d6 {Print "您输入的增广矩阵如下："
For i = 1 To n
s = Trim(InputBox("请输入增广矩阵的第" & i & "行" + vbCrLf + "各元素之间请用空格分开", i & "行矩阵的输入"))
3 B% f# T& [' T+ U& ?( N- RFor j = 1 To n
a(i, j) = Val(Left(s, InStr(s, " ")))
. s0 t8 I' ?" W0 y! as = Trim(Right(s, (Len(s) - InStr(s, " "))))
Print a(i, j);
Next
a(i, n + 1) = Val(s)
Print a(i, n + 1);
Print
Next
6 X! N  \8 b/ y$ c
For k = 1 To n - 1 '开始消元
1 r1 u: r) [* {+ QIf a(k, k) = 0 Then
MsgBox " Sorry！解不出！" + vbCrLf + "原因是：a(" & k & "，" & k & ")=0了！", vbExclamation, "解不出呀！"
, [6 L& P% B  |# yExit Sub
Else
( E9 u9 s' J8 i$ b3 h2 vFor i = k + 1 To n
l(i, k) = a(i, k) / a(k, k)
For j = k + 1 To n + 1
3 _% }8 F. J5 ~( r! i. va(i, j) = a(i, j) - l(i, k) * a(k, j)
Next
Next
# L' z& Q2 T( l- N' d8 ^D = D * a(k, k)
End If
Next k '消元结束
7 {/ B6 O! f* \! y# ]. s7 }If a(n, n) = 0 Then
3 _. V  C$ o9 z; [: D, G3 ?2 SMsgBox "Sorry！“高斯法”对此矩阵无能为力！" + vbCrLf + "原因是：a(n.n)=0了", vbExclamation, "解不出呀！"
8 y, E7 T4 [% O) rExit Sub
Else
D = D * a(n, n)
, I# L; S4 g& `: D: wEnd If
( q3 t0 T9 O7 C, ]% n  wPrint "--------------------------------"
9 r2 |5 O- {6 ^1 iPrint "系数行列式的值是："; D
% j. R$ R0 `' d% q' Ox(n) = a(n, n + 1) / a(n, n)
9 A5 {+ d; q4 \For k = n - 1 To 1 Step -1 '开始回代
For j = k + 1 To n
: [' @( M( `8 f& |8 ^m = m + a(k, j) * x(j)
Next j
x(k) = (a(k, n + 1) - m) / a(k, k)
m = 0
Next k '结束回代

5 G4 K( u, w! s! ^. o! Z$ @Print "--------------------------------"
Print "方程组的解如下："

For k = 1 To n
Print
; a- K% k# c5 l! Z5 d' z. bPrint "X(" & k & ") = " & x(k)
* B/ j+ Y  B9 U$ Q  p. K" zNext k
Print "--------------------------------"
Print "其中各行Ax-b="
Print
8 x0 {4 H! {$ r# ]6 q- IFor i = 1 To n
t = 0
# B1 W  N$ |# \5 m+ tFor j = 1 To n
# f, x) ^, N+ z- M. {t = t + a2(i, j) * x(j)
5 O  I6 Y3 T) d% @  }( FNext j
0 x' Q' y6 j9 Ft = t - a2(i, n + 1)
$ q' R8 Q% Q* h. O1 V/ Y3 V( Y# ePrint Spc(5); "第" & i & "行："; t
- H# g  ^1 X/ K! n8 e/ sPrint
Next i

5 w  D" K  w* L  O! s* t+ {* iEnd Sub

ch123en123

下载学习哦

lq12131010

<p>您的程序我没看&nbsp; 但是我用FORTRAN 90 编过 </p><p>唯一注意的是高斯消法是有局限的 </p><p>1计算量大</p><p>2不能克服病态方程问题。</p><p>不知道您注意没有 </p><p>另我有FORTRAN 90&nbsp;的选主元高斯消去法的程序。</p>

zqyzixin

我也想了解了解！！！先顶一个