【求助】請幫我看一下這個vb程式碼哪邊錯了

**hackerbobo** · 2005-01-07, 02:53 AM

執行會出現錯誤

== 第一部分.宣告 ==

'---設定Visual Basic選項---
Option Explicit

'---針對節點開一個11x11的矩陣---
Dim M(1 To 11, 1 To 11) As Double
Dim i As Integer, j As Integer
'---宣告區段到此結束.以下是執行程序---

' == 第二部分.初始假設 ==

'---假定矩陣各元素之初始值(由0開始)---
Private Sub Command1_Click()

M(1, 1) = 0: M(1, 2) = 0: M(1, 3) = 0: M(1, 4) = 0: M(1, 5) = 0: M(1, 6) = 0: M(1, 7) = 0: M(1, 8) = 0: M(1, 9) = 0: M(1, 10) = 0: M(1, 11) = 0
M(2, 1) = 0: M(2, 2) = 0: M(2, 3) = 0: M(2, 4) = 0: M(2, 5) = 0: M(2, 6) = 0: M(2, 7) = 0: M(2, 8) = 0: M(2, 9) = 0: M(2, 10) = 0: M(2, 11) = 0
M(3, 1) = 0: M(3, 2) = 0: M(3, 3) = 0: M(3, 4) = 0: M(3, 5) = 0: M(3, 6) = 0: M(3, 7) = 0: M(3, 8) = 0: M(3, 9) = 0: M(3, 10) = 0: M(3, 11) = 0
M(4, 1) = 0: M(4, 2) = 0: M(4, 3) = 0: M(4, 4) = 0: M(4, 5) = 0: M(4, 6) = 0: M(4, 7) = 0: M(4, 8) = 0: M(4, 9) = 0: M(4, 10) = 0: M(4, 11) = 0
M(5, 1) = 0: M(5, 2) = 0: M(5, 3) = 0: M(5, 4) = 0: M(5, 5) = 0: M(5, 6) = 0: M(5, 7) = 0: M(5, 8) = 0: M(5, 9) = 0: M(5, 10) = 0: M(5, 11) = 0
M(6, 1) = 0: M(6, 2) = 0: M(6, 3) = 0: M(6, 4) = 0: M(6, 5) = 0: M(6, 6) = 0: M(6, 7) = 0: M(6, 8) = 0: M(6, 9) = 0: M(6, 10) = 0: M(6, 11) = 0
M(7, 1) = 0: M(7, 2) = 0: M(7, 3) = 0: M(7, 4) = 0: M(7, 5) = 0: M(7, 6) = 0: M(7, 7) = 0: M(7, 8) = 0: M(7, 9) = 0: M(7, 10) = 0: M(7, 11) = 0
M(8, 1) = 0: M(8, 2) = 0: M(8, 3) = 0: M(8, 4) = 0: M(8, 5) = 0: M(8, 6) = 0: M(8, 7) = 0: M(8, 8) = 0: M(8, 9) = 0: M(8, 10) = 0: M(8, 11) = 0
M(9, 1) = 0: M(9, 2) = 0: M(9, 3) = 0: M(9, 4) = 0: M(9, 5) = 0: M(9, 6) = 0: M(9, 7) = 0: M(9, 8) = 0: M(9, 9) = 0: M(9, 10) = 0: M(9, 11) = 0
M(10, 1) = 0: M(10, 2) = 0: M(10, 3) = 0: M(10, 4) = 0: M(10, 5) = 0: M(10, 6) = 0: M(10, 7) = 0: M(10, 8) = 0: M(10, 9) = 0: M(10, 10) = 0: M(10, 11) = 0
M(11, 1) = 0: M(11, 2) = 0: M(11, 3) = 0: M(11, 4) = 0: M(11, 5) = 0: M(11, 6) = 0: M(11, 7) = 0: M(11, 8) = 0: M(11, 9) = 0: M(11, 10) = 0: M(11, 11) = 0

'------------------------------------------------------------------------------------------------------------------------------------------------------------

' == 第三部分.運算部分 ==

'---1.計算邊界數值---
If 1 <= i <= 11 And j = 1 Then
M(i, j) = 0 + i * (30 / 10)
End If

If 1 <= i <= 11 And j = 11 Then
M(i, j) = 50 + i * (50 / 10)
End If

If 2 <= j <= 10 And i = 1 Then
M(i, j) = 0 + j * (50 / 10)
End If

If 2 <= j <= 10 And i = 11 Then
M(i, j) = (2 * M(i - 1, j) + M(i, j - 1) + M(i, j + 1)) / 4
End If

'---2.計算內部數值(每個點之值=鄰近四點和/4)---
If 2 <= i <= 10 And 2 <= j <= 10 Then
M(i, j) = (M(i + 1, j) + M(i - 1, j) + M(i, j + 1) + M(i, j - 1)) / 4
End If

'-----------------------------------------------------------------------------------------------------------------------------------------------------------

' == 第四部分.迴圈結構 ==

'---Do Loop 由猜值推估修正到正確值---
Dim O As Double
Dim N As Double
Do
If 2 <= i <= 10 And 2 <= j <= 10 Then
M(i, j) = (M(i + 1, j) + M(i - 1, j) + M(i, j + 1) + M(i, j - 1)) / 4
M(6, 6) = O
End If

If 2 <= j <= 10 And i = 11 Then
M(i, j) = (2 * M(i - 1, j) + M(i, j - 1) + M(i, j + 1)) / 4
End If

If 2 <= i <= 10 And 2 <= j <= 10 Then
M(i, j) = (M(i + 1, j) + M(i - 1, j) + M(i, j + 1) + M(i, j - 1)) / 4
M(6, 6) = N
End If

If 2 <= j <= 10 And i = 11 Then
M(i, j) = (2 * M(i - 1, j) + M(i, j - 1) + M(i, j + 1)) / 4
End If

Loop Until (O / N) <= 10 ^ (-5) '---如果(舊值/新值)<10^(-5),則離開迴圈---

'--------------------------------------------------------------------------------------------------------------------------------------------------

' == 第五部分.結果輸出 ==

'---將此問題的結果輸出(檔案名"solution")---

Open "solution" For Output As #1
Print #1, M(i, j)

End Sub

錯誤訊息是

執行階段錯誤 '9'

陣列索引超出範圍

偵錯後說

M(i, j) = (M(i + 1, j) + M(i - 1, j) + M(i, j + 1) + M(i, j - 1)) / 4

有問題

thx

**ivantw** · 2005-01-07, 12:44 PM

錯的一榻糊塗...

第三部份應該是如此吧？

語法:

        For i = 1 To 11
            For j = 1 To 11
                Select Case j
                   Case 1
                     M(i, j) = 0 + i * (30 / 10)
                   Case 11
                     M(i, j) = 50 + i * (50 / 10)
                   Case Else
                     Select Case i
                        Case 1
                          M(i, j) = 0 + j * (50 / 10)
                        Case 11
                          M(i, j) = (2 * M(i - 1, j) + M(i, j - 1) + M(i, j + 1)) / 4
                        Case Else
                          M(i, j) = (M(i + 1, j) + M(i - 1, j) + M(i, j + 1) + M(i, j - 1)) / 4
                     End Select
                End Select
            Next j
        Next i

第四部分錯的更離譜，沒For Next迴圈來Assign i,j的值，O與N也沒給初值，
測試條件 (O / N) <= 10 ^ (-5) <-- 肯定是一跑就錯誤 0/0 除數為零，迴圈中也沒指定新值給 O and N ，就算你給初值給 O and N這Do...Loop迴圈不是只跑一次，就是永不結束。

**hackerbobo** · 2005-01-08, 10:47 PM

這是經過ivan lin 指導修改過的可是還是有點問題請問哪邊還需要修改我第一次寫程式不知道如何表達我要達成的目的

Private Sub Command1_Click()
' == 第一部分.初始假設 ==
'---針對節點開一個11x11的矩陣---
Dim M(1 To 11, 1 To 11) As Double
Dim i As Integer
Dim j As Integer

Dim O As Double
Dim N As Double

'---假定矩陣各元素之初始值(由0開始)---
For i = 1 To 11
For j = 1 To 11
M(i, j) = 0
Next j
Next i

'-----------------------------------------------------------------------------------------------------------------------------------------------------------

' == 第二部分.運算部分 ==

'---1.計算邊界數值---
'1-1.下邊界數值
For i = 1 To 11
For j = 1 To 1
M(i, j) = 0 + i * (30 / 10)
Next j
Next i
'1-2.上邊界數值
For i = 1 To 11
For j = 11 To 11
M(i, j) = 50 + i * (50 / 10)
Next j
Next i
'1-3.左邊界數值
For i = 1 To 1
For j = 2 To 10
M(i, j) = 0 + j * (50 / 10)
Next j
Next i
'1-4.右邊界數值
For i = 11 To 11
For j = 2 To 10
Option Explicit

M(i, j) = (2 * M(10, j) + M(11, j - 1) + M(11, j + 1)) / 4
Next j
Next i

'---2.計算內部數值(每個點之值=鄰近四點和/4)---
For i = 2 To 10
For j = 2 To 10
M(i, j) = (M(i + 1, j) + M(i - 1, j) + M(i, j + 1) + M(i, j - 1)) / 4
Next j
Next i

'-----------------------------------------------------------------------------------------------------------------------------------------------------------

For i = 1 To 11
Debug.Print i, ;
For j = 1 To 11
'Debug.Print Left(M(i, j), 8), ;

Debug.Print Format(M(i, j), ".##########"), ;
Next j
Debug.Print
Next i

Debug.Print "M(6,6): "; M(6, 6)

'-----------------------------------------------------------------------------------------------------------------------------------------------------------
' == 第三部分.迴圈結構 ==

'---Do Loop 由猜值推估修正到正確值---
Do
'1.計算一次內部值,並取 M(6, 6)的數值作為舊值(O)
For i = 2 To 10
For j = 2 To 10
M(i, j) = (M(i + 1, j) + M(i - 1, j) + M(i, j + 1) + M(i, j - 1)) / 4
Next j
Next i
O = M(6, 6)
'2.計算一次右邊界值
For i = 11 To 11
For j = 2 To 10
M(i, j) = (2 * M(i - 1, j) + M(i, j - 1) + M(i, j + 1)) / 4
Next j
Next i
'3.再計算一次內部值,並取 M(6, 6)的數值作為新值(N)
For i = 2 To 10
For j = 2 To 10
M(i, j) = (M(i + 1, j) + M(i - 1, j) + M(i, j + 1) + M(i, j - 1)) / 4
Next j
Next i
N = M(6, 6)
'4.再計算一次右邊界值
For i = 11 To 11
For j = 2 To 10
M(i, j) = (2 * M(i - 1, j) + M(i, j - 1) + M(i, j + 1)) / 4
Next j
Next i

Debug.Print O, N, (O / N)

DoEvents
Loop Until (O / N) <= 10 ^ (-1) '---如果(舊值/新值)<10^(-5),則離開迴圈---

MsgBox "ok"

'--------------------------------------------------------------------------------------------------------------------------------------------------

' == 第四部分.結果輸出 ==

For i = 1 To 11
Debug.Print i, ;
For j = 1 To 11
'Debug.Print Left(M(i, j), 8), ;

Debug.Print Format(M(i, j), ".##########"), ;
Next j
Debug.Print
Next i

Debug.Print "M(6,6): "; M(6, 6)

'---將此問題的結果輸出(檔案名"solution")---

Open "solution" For Output As #1
Print #1, M(i, j)

End Sub

附上題目說明,謝謝!!
已知有一個流場的邊界如下圖所示：

而其中關於O與N的收斂值部分,我之前是問同學如何讓這個矩陣判定結束迴圈,我同學的建議是任一抽取其中的一個數值作為基準,在以此值計算的新值與舊值做比較來作為結束迴圈的條件.所以我才會作如此的假設.但是如此的假設似乎是造成無法跑出迴圈的原因,所以想請問能否有更好的方式呢?