Rescaling frame from RooFit

gistfile1.py

def rescale_frame(canvas, frame, scale, title):
    """
    HACK
    Takes a frame and rescales it to arbitrary coordinates. 
    This is helpful when dealing with RooPlot to get the axes
    correct.  Returns axis in case anything else needs to be done.
    """
    import ROOT
    yaxis = frame.GetYaxis()
    yaxis.SetTickLength(0)
    yaxis.SetNdivisions(0)
    yaxis.SetLabelSize(0)
    yaxis.SetTitle("")
    yaxis.SetLabelColor(10)
    yaxis.SetAxisColor(10)
    frame.Draw()
    canvas.Update()
    amax = frame.GetMaximum()
    amin = frame.GetMinimum()
    new_max = amax*scale
    new_min = amin*scale
    x = canvas.PadtoX
    y = canvas.PadtoY
    
    axis = ROOT.TGaxis(x(canvas.GetUxmin()), y(canvas.GetUymin()),
                       x(canvas.GetUxmin()), y(canvas.GetUymax()),
                       new_min,new_max,510,"")
    axis.SetTitle(title)
    axis.Draw()
    canvas.Update()
    return axis

# example usage 

    final_pdf.plotOn(frame, ROOT.RooFit.LineStyle(ROOT.kDashed),
                     ROOT.RooFit.Components("energy_pdf_flat*"))
    frame.Draw()
    myaxis = rescale_frame(c1, frame, scale, "Counts/kg")
    c1.Update()