X-Stream Operator’s Manual 
WM-OM-E Rev I  335 
curve, the result for a perfect DUT would be a horizontal line, which is easy to inspect. The example 
below has been magnified vertically by a factor of ten. The rise at the right side occurs because the 
signal is descending into the noise. 
 
 
Private Sub Command1_Click() 
'   Draw a DSO trace on a logarithmic horizontal scale. 
Dim WM As Object 
Set WM = CreateObject("LeCroy.XStreamApplication") 
  
Dim Samples As Long 
Samples = WM.Math.F1.Out.Result.Samples 
Samples = Samples - 1 ' Make it a round number. 
'   Calculate the horizontal scale. 
LogSamples = Log(Samples) 
XScale = Samples / LogSamples 
  
'   Set the scale using DSO variables 
Dim Top, Bot As Single 
Top = WM.Math.F1.Out.Result.VerticalFrameStop 
Bot = WM.Math.F1.Out.Result.VerticalFrameStart 
Picture1.Scale (0, Top)-(Samples, Bot) 
  
Dim Wave 
Wave = WM.Math.F1.Out.Result.DataArray 
  
Dim Black, White, Blue, Red As Long 
Black = 0: White = &HFFFFFF 
Blue = &HFF4444: Red = &HFF 
  
'   Draw a theoretical curve for the peaks. 
StartPoint = Top + 20#: EndPoint = -54.5 
Picture1.Line (0, StartPoint)-(Samples, EndPoint), Red 
  
'  Draw the plot with linear interpolation between points. 
    For X = 1 To Samples 
    LogX = XScale * Log(X): Y = Wave(X) 
        If X > 1 Then 
        Picture1.Line (LogX, Y)-(OldLogX, OldWave), Black