code: def get_mean_and_stddevs(self, sites, rup, dists, imt, stddev_types):
          
          C = self.COEFFS[imt]
  
          mag = rup.mag - 6
          d = np.sqrt(dists.rjb ** 2 + C['c7'] ** 2)
          mean = np.zeros_like(d)
  
          mean += C['c1'] + C['c2'] * mag + C['c3'] * mag ** 2 + C['c6']
  
          idx = d <= 100.
          mean[idx] = mean[idx] + C['c5'] * np.log10(d[idx])
  
          idx = d > 100.
          mean[idx] = (mean[idx] + C['c5'] * np.log10(100.) -
                       np.log10(d[idx] / 100.) + C['c4'] * (d[idx] - 100.))
  
          # convert from log10 to ln and from cm/s**2 to g
          mean = np.log((10.0 ** (mean - 2.0)) / g)
  
          stddevs = self._get_stddevs(C, stddev_types,  dists.rjb.shape[0])
  
          return mean, stddevs
docs: See :meth:`superclass method
          <.base.GroundShakingIntensityModel.get_mean_and_stddevs>`
          for spec of input and result values.