Reputation: 4097
I have an Excel sheet with date and email address columns, sorted by date. I want to count the number of times an email address is in the sheet prior to the current occurrence. The COUNTIF(B$1:B1,B2) formula works but when I copy it down to more than 50,000 records Excel crashes. I have 200,000 records total.
Is there another solution that Excel (2010) can handle?
Upvotes: 1
Views: 2061
Reputation: 53166
Here's a VBA sub that runs in a reasonable time
Sub countPrior()
Dim dic As Object
Dim i As Long
Dim dat As Variant
Dim dat2 As Variant
' Get source data range, copy to variant array
dat = Cells(1, 2).Resize(Cells(Rows.Count, 1).End(xlUp).Row, 1)
' create array to hold results
ReDim dat2(1 To UBound(dat, 1), 1 To 1)
' use Dictionary to hold count values
Set dic = CreateObject("scripting.dictionary")
' loop variant array
For i = 1 To UBound(dat, 1)
If dic.Exists(dat(i, 1)) Then
' return count
dat2(i, 1) = dic.Item(dat(i, 1))
' if value already in array, increment count
dic.Item(dat(i, 1)) = dic.Item(dat(i, 1)) + 1
Else
' return count
dat2(i, 1) = 0
' if value not already in array, initialise count
dic.Add dat(i, 1), 1
End If
Next
' write result to sheet
Cells(1, 3).Resize(Cells(Rows.Count, 1).End(xlUp).Row, 1) = dat2
End Sub
Upvotes: 1
Reputation: 19592
If macros are an option for you, here is a macro that will accomplish this for you. I have assumed your address is in column B and you wish to record the number of prior occurrences in column C, you can modify it for the way your sheet is structured.
Sub countPrior()
Application.ScreenUpdating=False
bottomRow = Range("B1000000").End(xlUp).Row
For i = 2 To bottomRow
cellVal = Range("B" & i).Value
counter = 0
For j = 1 To i - 1
If Range("B" & j).Value = cellVal Then
counter = counter + 1
End If
Next j
Range("C" & i).Value = counter
Next i
Application.ScreenUpdating=True
End Sub
Upvotes: 0