Question

已更新 我解决后正在清理这篇文章。总而言之，我正在为excel制作用户定义的公式，计算下一个最高素数（=NextHighestPrimeNumber(100)返回101）。当我开始尝试时，我注意到公式会出现大约21亿的错误。我以为它可能已连接到我的变量所以我尝试了DOUBLE，但我仍然收到错误。

这是功能：

Function NextHighestPrimeNumber(StartingNumber As Double) As Variant
Dim CeilingTest As Long
Dim i As Long

If StartingNumber < 11 Then
            If StartingNumber > 6 Then
                NextHighestPrimeNumber = 11

            ElseIf StartingNumber > 4 Then
                NextHighestPrimeNumber = 7

            ElseIf StartingNumber > 2 Then
                NextHighestPrimeNumber = 5

            ElseIf StartingNumber > 0 Then
                NextHighestPrimeNumber = 3

            ElseIf StartingNumber = 0 Then
                NextHighestPrimeNumber = 1

            Else
                NextHighestPrimeNumber = "Pick A Positive Integer"

            End If

        Exit Function

Else

    'Create Array
    ReDim Prime_Array(0 To 4) As Double
    GoTo StartArrayPopulate
DoneWithStartingArray:

    If StartingNumber Mod 2 = 0 Then
        StartingNumber = StartingNumber - 1
    End If

NewNumber:
        StartingNumber = StartingNumber + 2
        CeilingTest = Int(VBA.Sqr(StartingNumber))


    'Array loop
    For i = LBound(Prime_Array) To UBound(Prime_Array)
        If Prime_Array(i) > CeilingTest Then
            NextHighestPrimeNumber = StartingNumber
            Exit Function
        ElseIf StartingNumber Mod Prime_Array(i) = 0 Then GoTo NewNumber

        End If
    Next i


    'Add new Array Value
ExpandDim:
    ReDim Preserve Prime_Array(UBound(Prime_Array) + 1)
    Prime_Array(UBound(Prime_Array)) = NextHighestPrimeNumber(Prime_Array(UBound(Prime_Array) - 1))

    'test if bigger than cieling
    If Prime_Array(UBound(Prime_Array)) > CeilingTest Then
        NextHighestPrimeNumber = StartingNumber
        Exit Function

    ElseIf StartingNumber Mod Prime_Array(UBound(Prime_Array)) = 0 Then GoTo NewNumber


    Else
        GoTo ExpandDim
    End If

End If


Exit Function

StartArrayPopulate:


Prime_Array(0) = 3
Prime_Array(1) = 5
Prime_Array(2) = 7
Prime_Array(3) = 11
Prime_Array(4) = 13


GoTo DoneWithStartingArray

End Function

Answer 1

问题是因为VBA MOD函数 ALWAYS 将分子转换为LONG变量，即使它先前被定义为Double或者是硬编码数字！

测试自己：

MsgBox (2147483647) mod 3 'Maximum Long Value

Vs以上。

MsgBox (2147483647 + 1) mod 3'Oh False!

我使用INT函数复制mod计算Numerator -(INT(Numerator /Denominator)*Denominator)，但还有很多其他创造性的方法可以避免。即使具有excel MOD功能的Evaluate也能正常工作。

底线：我永远不会将MOD用于任何可能超过20亿的计算

自从我的第一篇帖子以来，我已经清理了我的代码，并将坏行注释掉，这些错误标记了`zz failed code：

Function NextHighestPrimeNumber(StartingNumber As Double) As Variant
Dim CeilingTest As Long
Dim i As Long


If StartingNumber < 11 Then
            If StartingNumber > 6 Then
                NextHighestPrimeNumber = 11

            ElseIf StartingNumber > 4 Then
                NextHighestPrimeNumber = 7

            ElseIf StartingNumber > 2 Then
                NextHighestPrimeNumber = 5

            ElseIf StartingNumber > 0 Then
                NextHighestPrimeNumber = 3

            ElseIf StartingNumber = 0 Then
                NextHighestPrimeNumber = 1

            Else
                NextHighestPrimeNumber = "Pick A Positive Integer"

            End If

        Exit Function

Else

    'Create Array
    ReDim Prime_Array(0 To 4) As Double
    GoTo StartArrayPopulate
DoneWithStartingArray:

    'zz failed code: If StartingNumber Mod 2 = 0 Then
    If StartingNumber - (Int(StartingNumber / 2) * 2) = 0 Then
        StartingNumber = StartingNumber - 1
    End If

NewNumber:
        StartingNumber = StartingNumber + 2
        CeilingTest = INT(VBA.Sqr(StartingNumber))


    'Array loop
    For i = LBound(Prime_Array) To UBound(Prime_Array)
        If Prime_Array(i) > CeilingTest Then
            NextHighestPrimeNumber = StartingNumber
            Exit Function
        'zz failed code: ElseIf StartingNumber Mod Prime_Array(i) = 0 Then 
GoTo NewNumber
        ElseIf StartingNumber - (Int(StartingNumber / Prime_Array(i)) * Prime_Array(i)) = 0 Then GoTo NewNumber
        End If
    Next i


    'Add new Array Value
ExpandDim:
    ReDim Preserve Prime_Array(UBound(Prime_Array) + 1)
    Prime_Array(UBound(Prime_Array)) = NextHighestPrimeNumber(Prime_Array(UBound(Prime_Array) - 1))

    'test if bigger than ceiling
    If Prime_Array(UBound(Prime_Array)) > CeilingTest Then
        NextHighestPrimeNumber = StartingNumber
        Exit Function

    'zz failed code: ElseIf StartingNumber Mod Prime_Array(UBound(Prime_Array)) = 0 Then GoTo NewNumber
    ElseIf StartingNumber - (Int(StartingNumber / Prime_Array(UBound(Prime_Array))) * Prime_Array(UBound(Prime_Array))) = 0 Then GoTo NewNumber

    Else
        GoTo ExpandDim
    End If

End If


Exit Function

StartArrayPopulate:   
Prime_Array(0) = 3
Prime_Array(1) = 5
Prime_Array(2) = 7
Prime_Array(3) = 11
Prime_Array(4) = 13

GoTo DoneWithStartingArray

End Function

MOD函数在Excel VBA中独家使用长变量

1 个答案: