Need to pare down huge data file for plotting

hi, Alex, please check attachment, run code "test", the data is supposed to start from A1 cell

watersev
When I try to download your file, I get a [Microsoft Visual Basic - File not Found] error message, twice; and then another error message regarding 'unreadable contents'.

But I would really like to see your proposed approach!

Marcol
I understand your approach, but the data extends beyond one column.

For example, I just opened the file from one of this morning's tests.
The data to plot for three of the spreadsheets extends from columns A through N (for all three sheets), and the number of rows are 54005, 67992, and 41449.

Thanks for following up!

Alex

uploaded again, though it's ok for me when downloaded from post # 2 (files are identical, just in case in two different formats)

The code itself provided data starts in A1 cell:

Sub test()

Dim main As Workbook, NewWkb As Workbook, x, y, i As Long, n As Long, j As Long

Application.ScreenUpdating = 0

Set main = ActiveWorkbook
Set NewWkb = Workbooks.Add

For Each sh In main.Sheets

    x = sh.Range("a1").CurrentRegion
    colcount = UBound(x, 2)
    ReDim y(1 To UBound(x), 1 To colcount)

    For i = 25 To UBound(x) Step 25
    
        j = j + 1
        
        For n = 1 To colcount
        
            y(j, n) = x(i, n)
        
        Next
    
    Next

    Sheets.Add after:=Sheets(Sheets.Count)
    ActiveSheet.Name = sh.Name
    Range("a1").Resize(j, colcount) = y
    
    j = 0
    
Next

Application.ScreenUpdating = 1

End Sub

watersev
That worked perfectly - exactly what I needed!

Thank You !!!!!!!!!!!!!!!!!!!

Alex