Excel VBA UDF数组函数对所有cel返回相同的值

Question

I'm trying to make my Excel VBA UDF function to return an array. As of now the function either returns #VALUE! error if I define the argument as double array or all of the cells in the array have the same value if I define the argument as variant even though I checked in the Locals window in VBE and the return array variable actually contains different values.

Here is my code:

Function VaRScenariosTest(ByRef dblRealRates() As Double/Variant) As Double()
'dblRealRates() is defined as either Double or Variant
Dim intCount As Integer
Dim dblTemp() As Double

For intCount = LBound(dblRealRates) To (UBound(dblRealRates) - 1)
  ReDim Preserve dblTemp(1 To intCount)
  dblTemp(intCount) = dblRealRates(intCount + 1) - dblRealRates(intCount)
Next intCount

VaRScenariosTest = dblTemp

End Function

Function Range2dblArray(ByRef rngRange As Range) As Double()

Dim dblTemp() As Double
Dim intCount As Integer

For intCount = 1 To rngRange.Count
  ReDim Preserve dblTemp(1 To intCount)
  dblTemp(intCount) = rngRange.Cells(intCount)
Next intCount

Range2dblArray = dblTemp

End Function

I call the function in the spreadsheet in the following way: function call in excel with dblRealRates() as Double/Variant

Column E contains the input to function, column F the values that should be returned by the function and column G the function itself. If I define the dblRealRates() variable type as double, the formula returns the #VALUE! error. If I define it as variant, the returned values in the spreadsheet are the same. If I pause the execution of the code at End Function line and look in the Locals WIndow, you can actually see that the values in the array are different, not all equal to 0.000016287 as the output in the spreadsheet suggests: Function Array values in Locals Window

Can someone please advise why does the formula returns an error when the dblRealRates() variable is defined as double, and why does it return identical values if it's defined as variant?

Answer 1

A one-dimensional array is treated as being shaped as one row by x columns, so that is why your values are always coming out the same. (The entire result column is assigned the value of the first column returned.)

The following code works for your situation (but will undoubtedly give issues if you change things to work on rows instead of columns):

Function VaRScenariosTest(ByRef dblRealRates() As Variant) As Variant()
    Dim intCount As Integer
    Dim dblTemp() As Double

    For intCount = LBound(dblRealRates) To (UBound(dblRealRates) - 1)
        ReDim Preserve dblTemp(1 To intCount)
        dblTemp(intCount) = dblRealRates(intCount + 1, 1) - dblRealRates(intCount, 1)
    Next intCount

    VaRScenariosTest = Application.Transpose(dblTemp)
End Function

Function Range2dblArray(ByRef rngRange As Range) As Variant()
    Dim dblTemp() As Double
    Dim intCount As Integer

    For intCount = 1 To rngRange.Count
        ReDim Preserve dblTemp(1 To intCount)
        dblTemp(intCount) = rngRange.Cells(intCount)
    Next intCount

    Range2dblArray = Application.Transpose(dblTemp)
End Function

---

Alternatively, by doing the transpose of the results of Range2dblArray in the Excel formula itself

{=VaRScenariosTest(TRANSPOSE(Range2dblArray(E2:E21)))}

you can leave the original Range2dblArray untouched and only modify VaRScenariosTest :

Function VaRScenariosTest(ByRef dblRealRates() As Variant) As Variant()
    Dim intCount As Integer
    Dim dblTemp() As Double

    For intCount = LBound(dblRealRates) To (UBound(dblRealRates) - 1)
        ReDim Preserve dblTemp(1 To intCount)
        dblTemp(intCount) = dblRealRates(intCount + 1, 1) - dblRealRates(intCount, 1)
    Next intCount

    VaRScenariosTest = Application.Transpose(dblTemp)
End Function

Function Range2dblArray(ByRef rngRange As Range) As Double()
    Dim dblTemp() As Double
    Dim intCount As Integer

    For intCount = 1 To rngRange.Count
        ReDim Preserve dblTemp(1 To intCount)
        dblTemp(intCount) = rngRange.Cells(intCount)
    Next intCount

    Range2dblArray = dblTemp
End Function

---

And by also doing the transpose of the results of VaRScenariosTest in the Excel formula itself

{=TRANSPOSE(VaRScenariosTest(TRANSPOSE(Range2dblArray(E2:E21))))}

you can allow VaRScenariosTest to also return a one-dimensional array (but will still need to pass dblRealRates into the function as a two-dimensional Variant array):

Function VaRScenariosTest(ByRef dblRealRates() As Variant) As Double()
    Dim intCount As Integer
    Dim dblTemp() As Double

    For intCount = LBound(dblRealRates) To (UBound(dblRealRates) - 1)
        ReDim Preserve dblTemp(1 To intCount)
        dblTemp(intCount) = dblRealRates(intCount + 1, 1) - dblRealRates(intCount, 1)
    Next intCount

    VaRScenariosTest = dblTemp
End Function

Function Range2dblArray(ByRef rngRange As Range) As Double()
    Dim dblTemp() As Double
    Dim intCount As Integer

    For intCount = 1 To rngRange.Count
        ReDim Preserve dblTemp(1 To intCount)
        dblTemp(intCount) = rngRange.Cells(intCount)
    Next intCount

    Range2dblArray = dblTemp
End Function

Answer 2

Finally settled on the following version, as per @YowE3K guidance:

Function VaRScenariosTest(ByRef dblRealRates() As Variant) As Variant()
    Dim intCount As Integer
    Dim dblTemp() As Double

    For intCount = LBound(dblRealRates) To (UBound(dblRealRates) - 1)
        ReDim Preserve dblTemp(1 To intCount)
        dblTemp(intCount) = dblRealRates(intCount + 1) - dblRealRates(intCount)
    Next intCount

    VaRScenariosTest = Application.Transpose(dblTemp)
End Function

Function Range2Array(ByRef rngRange As Range) As Variant()
    Dim varTemp() As variant
    Dim intCount As Integer

    For intCount = 1 To rngRange.Count
        ReDim Preserve varTemp(1 To intCount)
        varTemp(intCount) = rngRange.Cells(intCount)
    Next intCount

    Range2Array = varTemp
End Function

Works well when used in a spreadsheet, and only the data types of the function VarScenariosTest and array argument dblRealRates() have to be changed back to double if I want to use exclusively in VBA, not in the spreadsheet, although the variant version would work here as well. @YowE3K thank you for your help!