code: def meantdAngle(self,dangle):
          
          Tlow= dangle/(self._meandO+3.*numpy.sqrt(self._sortedSigOEig[2]))
          Thigh= dangle/(self._meandO-3.*numpy.sqrt(self._sortedSigOEig[2]))
          num= integrate.quad(lambda x: x*self.ptdAngle(x,dangle),
                                Tlow,Thigh)[0]
          denom= integrate.quad(self.ptdAngle,Tlow,Thigh,(dangle,))[0]
          if denom == 0.: return self._tdisrupt
          elif numpy.isnan(denom): return 0.
          else: return num/denom
docs: NAME:
  
             meantdAngle
  
          PURPOSE:
  
             calculate the mean stripping time at a given angle
  
          INPUT:
  
             dangle - angle offset along the stream
  
          OUTPUT:
  
             mean stripping time at this dangle
  
          HISTORY:
  
             2013-12-05 - Written - Bovy (IAS)