Multiply Entire Range By Value?

Question

So The best way I could think of to accomplish this over a large range (about 450k rows) was to use the following Sue-do code:

Range(\"A1\").Copy \' A1 Cont         


        

Answer 1

Do not update cell by cell. It is very slow and there is a better way with VBA. Here is the outline:

1. Set a Range to all rows/columns needed to process
2. Copy values into array in VBA
3. Process the array
4. Write the array back into the worksheet in one operation

Here is an example:

Public Sub FactorRange(ByRef r_first as Range, ByVal N_rows as Long, _
ByVal N_cols as Long, ByVal factor as Double)
    Dim r as Range
    'Set range from first cell and size
    Set r = f_first.Resize(N_rows,N_cols)
    Dim vals() as Variant
    ' Copy cell values into array
    vals = r.Value
    Dim i as Long, j as Long
    ' Do the math
    For i=1 to N_rows
      For j=1 to N_cols
        vals(i,j) = factor * vals(i,j)
      Next j
    Next i
    ' Write values back
    r.Value = vals
End Sub