Returning two similar values from two different columns
 

Hi guys,

Basically i have a set of data plotted on an x-y scatter plot where at a single point the two curves cross over each other and meet at a single point, i.e. 'x and y values are both the same where they cross.

Im trying to determine this operating point by generating lookup tables for both each curve.,

for example in the x axis i need to match the same x value for one curve '1st lookup table row' with the same x value of the other curve '2nd lookup table row'. But the corresponding y values also need to be matching or relatively close to find the right point. Any ideas how this can be achieved, i was thinking of using a VLOOKUP and INDEX functions but it's much more complicated than that.

Any advice would be great,

Returning two similar values from two different columns
 

This might help. Suppose the source of the two lines is Range("B2:C25") on Sheet1.

Sub FindCrossover()
Dim dDiff(2 To 25) As Double
Dim dMin As Double
Dim iCt As Integer
Dim iX As Integer
For iCt = 2 To 25
dDiff(iCt) = Sheet1.Cells(iCt, "B") - Sheet1.Cells(iCt, "C")
Next iCt
For iCt = 3 To 25
If (dDiff(iCt) = 0 And dDiff(iCt - 1) < 0) _
Or (dDiff(iCt) <= 0 And dDiff(iCt - 1) 0) Then
'found crossover
iX = iCt
dMin = Abs(dDiff(iCt))
If Abs(dDiff(iCt - 1)) < Abs(dDiff(iCt)) Then
dMin = dDiff(iCt - 1)
iX = iCt - 1
End If
Debug.Print iX, Sheet1.Cells(iX, "B"), Sheet1.Cells(iX, "C")
Exit For
End If
Next iCt
End Sub