VBA: Set range to columns in different worksheets - vba

Question

I am trying to run the LinEst function through VBA. The problem that I am having is that my X-variables are in the same column but on different worksheets.
My question: Is it possible to combine these columns from the different sheets to one range?
Below is my attempt to code but it gets stuck on the Union part. I provided my sample as well.
Thank you in advance!
Sub FM()
Dim sResult As Worksheet
Set sResult = Sheets("Result")
Dim sY As Worksheet
Set sY = Sheets("Y")
Dim sX1 As Worksheet
Set sX1 = Sheets("X1")
Dim sX2 As Worksheet
Set sX2 = Sheets("X2")
Dim sX3 As Worksheet
Set sX3 = Sheets("X3")
Dim sX4 As Worksheet
Set sX4 = Sheets("X4")
Dim x() As Variant
ReDim x(1 To 4)
x(1) = sX1.Columns("A")
x(2) = sX2.Columns("A")
x(3) = sX3.Columns("A")
x(4) = sX4.Columns("A")
Dim rY As Range
Set rY = sY.Columns("A")
sResult.Range("B2").Value = Application.WorksheetFunction.LinEst(rY, x, True, True)(1, 4)
End Sub
Sample

Answer 1

In your update, x is an Array of Range objects but it needs to be an array of values from each respective range. That is almost certainly the mismatch error.
Resolving that, you'll need to fix your ranges, too, because it seems unlikely that you're using 4 million rows of data (Excel 2007+ has 1048576 rows per worksheet). We can use a method from this answer to help obtain the last row with data from a given column range.
This should get your x values and put them in an array known_x and the known_y array also, which you can use in your LineEst function.
Dim known_x() 'Will contain all of your x values
Dim known_y()
Dim i As Long
Dim rng As Variant
Dim val As Variant
Dim ws As Variant
Dim obs As Long
Dim SHEET_NAMES As String 'Comma-separated list of worksheets
SHEET_NAMES = "X1,X2,X3,X4"
'## Gets the size of the array needed to contain all of the values
For Each ws In Worksheets(Split(SHEET_NAMES, ","))
With ws
obs = obs + GetLastRow(.Columns(1))
End With
Next
ReDim known_x(1 To obs)
'## Dump the values in to the array
i = 1
For Each ws In Worksheets(Split(SHEET_NAMES, ","))
With ws
Set rng = .Range("A1:A" & GetLastRow(.Columns(1)))
For Each val In rng.Value
known_x(i) = val
i = i + 1
Next
End With
Next
'## Dump your y in to an array
With Worksheets("Sheet2")
Set rng = .Range("A1:A" & GetLastRow(.Columns(1)))
known_y = Application.Transpose(rng.Value))
End With
NOTE: If you are in fact using 4 million+ observations, then I think your known_y's parameter may be wrong, because that should be the same size as known_x's in the LinEst function, and you will need to add logic to ensure the arrays are the same size, etc.
NOTE: I've no idea what you're doing with (1, 4) at the end of your LinEst function call.

Answer 2

I don't want to put a useless answer, but if you play a bit with it, you will find something useful. And it produces some result in B2:
Option Explicit
Sub FM()
Dim sResult As Worksheet
Set sResult = Sheets(1)
Dim sY As Worksheet
Set sY = Sheets(2)
Dim sX1 As Worksheet
Set sX1 = Sheets(3)
Dim sX2 As Worksheet
Set sX2 = Sheets(4)
Dim sX3 As Worksheet
Set sX3 = Sheets(6)
Dim sX4 As Worksheet
Set sX4 = Sheets(5)
Dim x() As Variant
ReDim x(1 To 4)
x(1) = sX1.Cells(1, 1).Value
x(2) = sX1.Cells(2, 1).Value
x(3) = sX1.Cells(3, 1).Value
x(4) = sX1.Cells(4, 1).Value
Dim rY As Range
Set rY = sY.Range(sY.Cells(1, 1), sY.Cells(5, 1))
sResult.Range("B2").Value = Application.WorksheetFunction.LinEst(rY(1, 1), x(1), True, True)
End Sub
The problem is mainly in the way you refer to Arrays and Ranges. Check all of them again and you can make a workable solution.