Using function in VBA excel - vba

Question

I have been working on this code for a while. As you can see after the code line " With ws(2)" there is an if condition. Now, I have multiple to create multiple such If conditions such as for 0.6, 0.7, 0.8 etc. (and each such condition should use a different table of data) {I am posting the excel file link for the tables as well so that you can get an idea} Can I do this using a function or any method which wont require me to write this code again and again for each new condition ?
https://docs.google.com/file/d/0B1DVNSutDHR0QWd2UUJsVDZ1Tm8/edit
Private Sub CommandButton1_Click()
Dim x(1 To 9000) As Double, y(1 To 9000) As Double, x1 As Double, y1 As Double, x2 As Double, y2 As Double, I1(1 To 9000) As Double, I2(1 To 9000) As Double, R1(1 To 9000) As Double, R2(1 To 9000) As Double, a As Double, b As Double, c As Double, d As Double, Result(1 To 9000) As Double
Dim i As Integer, j As Integer, k As Integer, p As Integer, q As Integer, r As Integer, s As Integer, t As Integer
Dim ws As Sheets
Set ws = ActiveWorkbook.Sheets(Array("Sheet1", "PLP-1", "PLP-2"))
For t = 0 To 120 Step 20
For k = 1 To 9000
With ws(1)
I1(k) = .Cells(k + 2, 13).Value
I2(k) = .Cells(k + 2, 14).Value
End With
With ws(2)
Select Case .Cells(6 + t, 1).Value
Case 0.5:
r = 0
s = 0
Case 0.6:
r = 20
s = 1
Case 0.7:
r = 40
s = 2
Case 0.8:
r = 60
s = 2
Case 0.9:
r = 80
s = 3
Case 1:
r = 100
s = 4
Case 1.1:
r = 120
s = 5
End Select
For i = 7 To 22
If (.Cells(i + r, 1).Value <= I1(k)) And (I1(k) <= .Cells(i + r + 1, 1).Value) And Not (IsEmpty(I1(k))) Then
p = i + r
x(k) = I1(k)
x1 = .Cells(i + r, 1).Value
x2 = .Cells(i + r + 1, 1).Value
End If
Next i
For j = 2 To 8
If (.Cells(6 + r, j).Value <= I2(k)) And (I2(k) <= .Cells(6 + r, j + 1).Value) And Not (IsEmpty(I2(k))) Then
q = j + r
y(k) = I2(k)
y1 = .Cells(6 + r, j).Value
y2 = .Cells(6 + r, j + 1).Value
End If
Next j
If p <> 0 And q <> 0 Then
a = .Cells(p, q).Value
b = .Cells(p, q + 1).Value
c = .Cells(p + 1, q).Value
d = .Cells(p + 1, q + 1).Value
End If
If I1(k) = Empty Then
R1(k) = 0
Else
R1(k) = (((y2 - y(k)) / (y2 - y1)) * a) + (((y(k) - y1) / (y2 - y1)) * b)
End If
If I2(k) = Empty Then
R2(k) = 0
Else
R2(k) = (((y2 - y(k)) / (y2 - y1)) * c) + (((y(k) - y1) / (y2 - y1)) * d)
End If
Result(k) = (((x2 - x(k)) / (x2 - x1)) * R1(k)) + (((x(k) - x1) / (x2 - x1)) * R2(k))
End With
With ws(1)
.Cells(k + 2, 15 + s).Value = Result(k)
End With
Next k
Next t
End Sub

Answer 1

Try using a Select Case statement as below:
Dim iStart As Long, iEnd As long, jStart As Long, jEnd As Long
'...
With ws(2)
Select Case .Cells(6, 1).Value
Case 0.5:
iStart = 7: iEnd = 22
jStart = 2: jEnd = 7
Case 0.6:
'Same as above but substitute new values for iStart etc.
End Select
For i = iStart To iEnd
'DO STUFF WITH i
Next i
For j = jStart To jEnd
'DO STUFF WITH j
Next j
End With
EDIT: Updated to reflect needs clarified in comments
A more in-depth explanation and usage guide for Select Case can be found here

Answer 2

With regard to your looping, if I understand your code, you need to loop through each "table", but your I and J refer to absolute addresses. What you want is to have I and J be relative to the desired table.
I just used values of 2 to 7, but if the tables are different sizes, you could certainly determine that with code; or even read them into a variant array and do your testing on the array (would often be faster).
So something like the following (pseudo code)
Option Explicit
'N is the Value that defines the proper table
Function DoYourThingOnProperRange(N As Double)
Dim C As Range
Dim I As Long, J As Long
With Sheet1.Columns(1)
Set C = .Find(what:=N, after:=Sheet1.Cells(Rows.Count, "A"), LookIn:=xlValues, _
lookat:=xlWhole, searchorder:=xlByRows, searchdirection:=xlNext)
If Not C Is Nothing Then
Set C = C.CurrentRegion 'C is now set to the proper table
'DoYourThing
'Here's just a dummy routine
For I = 2 To 7
For J = 2 To 7
Debug.Print C(I, J).Address
Next J
Next I
Else
'some kind or error routine for non-existent table
End If
End With
End Function