以目标为公式的目标寻求宏

Question

I'm grasping at straws here, so any help would be great (ie. I have no idea what I'm doing with VBA).

I'm trying to solve a circular reference problem in Excel by creating a goal seek macro - basically

1. S3 = M + S2 ,
2. S3 = L * G .

I want to goal seek S3 to equal L * G by changing M.

So, I've put

• L * G in cell H32 ,
• S3 in H18 ,
• M in G18 ,
• S2 in F18

and this is what I've gathered so far.

Sub GoalSeek()   
Dim x As Integer
x = Range("H32").Value    
Range("H18").GoalSeek Goal:=x, ChangingCell:=Range("G18")     
End Sub

I'm getting a "Reference is not valid" error, ideas? Thanks!

Answer 1

GoalSeek will throw an "Invalid Reference" error if the GoalSeek cell contains a value rather than a formula or if the ChangingCell contains a formula instead of a value or nothing.

The GoalSeek cell must contain a formula that refers directly or indirectly to the ChangingCell; if the formula doesn't refer to the ChangingCell in some way, GoalSeek either may not converge to an answer or may produce a nonsensical answer.

I tested your code with a different GoalSeek formula than yours (I wasn't quite clear whether some of the terms referred to cells or values).

For the test, I set:

  the GoalSeek cell  H18 = (G18^3)+(3*G18^2)+6
  the Goal cell      H32 =  11
  the ChangingCell   G18 =  0 

The code was:

Sub GSeek()
    With Worksheets("Sheet1")
        .Range("H18").GoalSeek _
        Goal:=.Range("H32").Value, _
        ChangingCell:=.Range("G18")
    End With
End Sub

And the code produced the (correct) answer of 1.1038, the value of G18 at which the formula in H18 produces the value of 11, the goal I was seeking.

Answer 2

I think your issue is that Range("H18") doesn't contain a formula. Also, you could make your code more efficient by eliminating x . Instead, change your code to

Range("H18").GoalSeek Goal:=Range("H32").Value, ChangingCell:=Range("G18")