Use VBA to multiply matrices and save results in text file - vba

Question

I would really appreciate it if someone could give me some help with this.
I am quite familiar with vba and I can write simple code and also customise code from others. I have written /customised/copied several pieces of vba code to do the following (where copied source is acknowledged):
Select 2 different csv files which represent 2 matrixes of same columns and same rows.
Multiply each respective cells from the matrices.
Return results.
Unfortunately I cannot seem to be able to get this to run.
Any idea what I have not done correctly?
Please see the code below. Thanks so much.
Code changed from previous version
Public Sub doIt()
Dim sourceFile As String
Dim destinationFile As String
Dim data As Variant
Dim result As Variant
Dim sourceFile2 As String
Dim datarain As Variant
sourceFile = "C:\file1.csv"
sourceFile2 = "C:\file2.csv"
destinationFile = "C:\file3.txt"
data = getDataFromFile(sourceFile, ",")
datarain = getDataFromFile(sourceFile2, ",")
If Not isArrayEmpty(data) Then
result = MMULT2_FUNC(data, datarain)
writeToCsv result, destinationFile, ","
Else
MsgBox ("Empty file")
End If
End Sub
Function MMULT2_FUNC(ByRef ADATA_RNG As Variant, _
ByRef BDATA_RNG As Variant)
Dim i As Long
Dim j As Long
Dim k As Long
Dim ANROWS As Long
Dim BNROWS As Long
Dim ANCOLUMNS As Long
Dim BNCOLUMNS As Long
Dim ADATA_MATRIX As Variant
Dim BDATA_MATRIX As Variant
Dim TEMP_MATRIX As Variant
On Error GoTo ERROR_LABEL
ADATA_MATRIX = ADATA_RNG
BDATA_MATRIX = BDATA_RNG
ANROWS = UBound(ADATA_MATRIX, 1)
BNROWS = UBound(BDATA_MATRIX, 1)
ANCOLUMNS = UBound(ADATA_MATRIX, 2)
BNCOLUMNS = UBound(BDATA_MATRIX, 2)
If ANCOLUMNS <> BNROWS Then: GoTo ERROR_LABEL
ReDim TEMP_MATRIX(1 To ANROWS, 1 To BNCOLUMNS)
For i = 1 To ANROWS
For j = 1 To BNCOLUMNS
TEMP_MATRIX(i, j) = 0
For k = 1 To ANCOLUMNS
TEMP_MATRIX(i, j) = TEMP_MATRIX(i, j) + ADATA_MATRIX(i, k) * _
BDATA_MATRIX(k, j)
Next k
Next j
Next i
MMULT2_FUNC = TEMP_MATRIX
Exit Function
ERROR_LABEL:
MMULT2_FUNC = Err.Number
End Function
Public Sub writeToCsv(parData As Variant, parFileName As String, parDelimiter As String)
If getArrayNumberOfDimensions(parData) <> 2 Then Exit Sub
Dim i As Long
Dim j As Long
Dim FileNum As Long
Dim locLine As String
Dim locCsvString As String
FileNum = FreeFile
If Dir(parFileName) <> "" Then Kill (parFileName)
Open parFileName For Binary Lock Read Write As #FileNum
For i = LBound(parData, 1) To UBound(parData, 1)
locLine = ""
For j = LBound(parData, 2) To UBound(parData, 2)
If IsError(parData(i, j)) Then
locLine = locLine & "#N/A" & parDelimiter
Else
locLine = locLine & parData(i, j) & parDelimiter
End If
Next j
locLine = Left(locLine, Len(locLine) - 1)
If i <> UBound(parData, 1) Then locLine = locLine & vbCrLf
Put #FileNum, , locLine
Next i
error_handler:
Close #FileNum
End Sub
Public Function isArrayEmpty(parArray As Variant) As Boolean
'Returns false if not an array or dynamic array that has not been initialised (ReDim) or has been erased (Erase)
If IsArray(parArray) = False Then isArrayEmpty = True
On Error Resume Next
If UBound(parArray) < LBound(parArray) Then isArrayEmpty = True: Exit Function Else: isArrayEmpty = False
End Function
Public Function getArrayNumberOfDimensions(parArray As Variant) As Long
'Returns the number of dimension of an array - 0 for an empty array.
Dim i As Long
Dim errorCheck As Long
If isArrayEmpty(parArray) Then Exit Function 'returns 0
On Error GoTo FinalDimension
'Visual Basic for Applications arrays can have up to 60000 dimensions
For i = 1 To 60001
errorCheck = LBound(parArray, i)
Next i
'Not supposed to happen
getArrayNumberOfDimensions = 0
Exit Function
FinalDimension:
getArrayNumberOfDimensions = i - 1
End Function
Private Function getDataFromFile(parFileName As String, parDelimiter As String, Optional parExcludeCharacter As String = "") As Variant
'parFileName is supposed to be a delimited file (csv...)
'parDelimiter is the delimiter, "," for example in a comma delimited file
'Returns an empty array if file is empty or can't be opened
'number of columns based on the line with the largest number of columns, not on the first line
'parExcludeCharacter: sometimes csv files have quotes around strings: "XXX" - if parExcludeCharacter = """" then removes the quotes
Dim locLinesList() As Variant
Dim locData As Variant
Dim i As Long
Dim j As Long
Dim locNumRows As Long
Dim locNumCols As Long
Dim fso As Variant
Dim ts As Variant
Const REDIM_STEP = 10000
Set fso = CreateObject("Scripting.FileSystemObject")
On Error GoTo error_open_file
Set ts = fso.OpenTextFile(parFileName)
On Error GoTo unhandled_error
'Counts the number of lines and the largest number of columns
ReDim locLinesList(1 To 1) As Variant
i = 0
Do While Not ts.AtEndOfStream
If i Mod REDIM_STEP = 0 Then
ReDim Preserve locLinesList(1 To UBound(locLinesList, 1) + REDIM_STEP) As Variant
End If
locLinesList(i + 1) = Split(ts.ReadLine, parDelimiter)
j = UBound(locLinesList(i + 1), 1) 'number of columns
If locNumCols < j Then locNumCols = j
If j = 13 Then
j = j
End If
i = i + 1
Loop
ts.Close
locNumRows = i
If locNumRows = 0 Then Exit Function 'Empty file
ReDim locData(1 To locNumRows, 1 To locNumCols + 1) As Variant
'Copies the file into an array
If parExcludeCharacter <> "" Then
For i = 1 To locNumRows
For j = 0 To UBound(locLinesList(i), 1)
If Left(locLinesList(i)(j), 1) = parExcludeCharacter Then
If Right(locLinesList(i)(j), 1) = parExcludeCharacter Then
locLinesList(i)(j) = Mid(locLinesList(i)(j), 2, Len(locLinesList(i)(j)) - 2) 'If locTempArray = "", Mid returns ""
Else
locLinesList(i)(j) = Right(locLinesList(i)(j), Len(locLinesList(i)(j)) - 1)
End If
ElseIf Right(locLinesList(i)(j), 1) = parExcludeCharacter Then
locLinesList(i)(j) = Left(locLinesList(i)(j), Len(locLinesList(i)(j)) - 1)
End If
locData(i, j + 1) = locLinesList(i)(j)
Next j
Next i
Else
For i = 1 To locNumRows
For j = 0 To UBound(locLinesList(i), 1)
locData(i, j + 1) = locLinesList(i)(j)
Next j
Next i
End If
getDataFromFile = locData
Exit Function
error_open_file: 'returns empty variant
unhandled_error: 'returns empty variant
End Function

Answer 1

Despite my personal impression that your code can be improved in some instances, it syntactically executes here with no problem (on small matrices).
My test data
1,2,3 2,3,4 20,26,32
2,3,4 X 3,4,5 = 29,38,47
3,4,5 4,5,6 38,50,62
The result is neatly written to a CSV.
Only obvious problem (here on Win 7 !) is that Sub writeToCsv -> Open parFileName ... fails due to lack of write permissions into the root directory. This might be not a problem on XP.
On a different token, I have the impression the code can be improved, but I may not understand the rationale behind some parts of your code.
examples
Function MMULT2_FUNC(ByRef ADATA_RNG As Variant, ByRef BDATA_RNG As Variant) ' missing type of result
Private Function getDataFromFile(...)
...
If j = 13 Then
j = j
End If ' whow ... if j <> 13 then j again equals j ;-)
finding upper and lower bounds of the matrices on input as well as on output could be simplified by large ...

Answer 2

Thank you all for your help. The reason why my code was not printing results was that I had this:If ANCOLUMNS <> BNROWS Then: GoTo ERROR_LABEL. At the same time, I was using two matrices of 70*120, so it constantly exited the function as I had programmed it to do!!Corrected it all and worked fine. Thanks a lot for your help