code: def targetSurfacemass(self,R,log=False):
           
           return self._surfaceSigmaProfile.surfacemass(R,log=log)
docs: NAME:
  
              targetSurfacemass
  
           PURPOSE:
  
              evaluate the target surface mass at R
  
           INPUT:
  
              R - radius at which to evaluate (can be Quantity)
  
              log - if True, return the log (default: False)
  
           OUTPUT:
  
              Sigma(R)
  
           HISTORY:
  
              2010-03-28 - Written - Bovy (NYU)