Goal Seek Iteration Code in VBA? Possible?

[dinosaur_uk]

Hi there,

I have an iteration which I want to use the principle of goal seek totally in vba without using the in-built excel one. Is this at all possible?

Sub Iterate()
Dim row As Integer
Dim i As Integer
Dim temp As Single
Dim flowCo As Single
Dim flowExp As Single
Dim PressCo As Single
Dim OJ As Single
Dim total As Single

Dim X As Single

R = 100

'3.441062516
Do Until total < 0.01 And total > 0
    'First need to calculate the O(J) Column
    row = Me.ListBox1.ListCount
    total = 0
    For i = 0 To row - 1
    temp = Me.ListBox1.List(i, 5)
    Me.ListBox1.List(i, 6) = R + temp
    
    'Now we calculate F(J)
    flowCo = Me.ListBox1.List(i, 2)
    flowExp = Me.ListBox1.List(i, 3)
    PressCo = Me.ListBox1.List(i, 4)
        
    OJ = Me.ListBox1.List(i, 6)
    Me.ListBox1.List(i, 7) = flowCo * ((Abs(OJ) ^ flowExp) * (OJ / Abs(OJ)))
    total = total + Me.ListBox1.List(i, 7)
    Next

If total < 0 Then
R = R + 0.1
Else
    If total > 1 Then
    R = R ^ 0.5
    ElseIf total > 0.1 Then
    R = R - 0.1
    ElseIf total > 0.01 Then
    R = R - 0.01
    End If 
End If


Loop

MsgBox R

'Now we need to sum it up



End Sub

I have tried all kinds of Tweaks and it does not seem to work

please help!

[VBAhack]

Perhaps you can adapt the code from this:

http://www.bmsltd.ie/DLCount/DLCount...e=GoalSeek.zip

[DKenny]

Or you could just call the GoalSeek method of the target cell.

Excel Developer Reference
Range.GoalSeek Method
Calculates the values necessary to achieve a specific goal. If the goal is an amount returned by a formula, this calculates a value that, when supplied to your formula, causes the formula to return the number you want. Returns True if the goal seek is successful.expression.GoalSeek(Goal, ChangingCell)
Return Value
Boolean

expression A variable that represents a Range object.

Parameters

Name Required/Optional Data Type Description
Goal Required Variant The value you want returned in this cell.
ChangingCell Required Range Specifies which cell should be changed to achieve the target value.

Example


This example assumes that Sheet1 has a cell named "Polynomial" that contains the formula =(X^3)+(3*X^2)+6 and another cell named "X" that’s empty. The example finds a value for X so that Polynomial contains the value 15.

Visual Basic for Applications
Worksheets("Sheet1").Range("Polynomial").GoalSeek _
Goal:=15, _
ChangingCell:=Worksheets("Sheet1").Range("X")