code: def _get_stddevs(self, C, stddev_types, mag, num_sites):
          
          stddevs = []
          for _ in stddev_types:
              if mag < 7.16:
                  sigma = C['c11'] + C['c12'] * mag
              elif mag >= 7.16:
                  sigma = C['c13']
              stddevs.append(np.zeros(num_sites) + sigma)
  
          return stddevs
docs: Return total standard deviation as for equation 35, page 1021.