Simon Mourier's Blog - Does VBA have an ATan2 function?

vb6-vba

Does VBA have an ATan2 function?

Feb 25, 2011 See the question and my original answer on StackOverflow

Maybe this code would suit you:

Private Const Pi As Double = 3.14159265358979

Public Function Atn2(y As Double, x As Double) As Double
  If x > 0 Then
    Atn2 = Atn(y / x)
  ElseIf x < 0 Then
    Atn2 = Sgn(y) * (Pi - Atn(Abs(y / x)))
  ElseIf y = 0 Then
    Atn2 = 0
  Else
    Atn2 = Sgn(y) * Pi / 2
  End If
End Function