code: def skew(self):
          r
          mn = self.mean
          sd = self.std
          sk = 0.0 if abs(sd) <= 1e-8 else np.mean((self._mcpts - mn) ** 3) / sd ** 3
          return sk
docs: r"""
          Skewness coefficient value as a result of an uncertainty calculation,
          defined as::
              
                _____     m3
              \/beta1 = ------
                        std**3
          
          where m3 is the third central moment and std is the standard deviation