code: def _get_site_amplification_term(self, C, vs30):
          
          f_s = np.zeros_like(vs30)
          # Site class B
          idx = np.logical_and(vs30 < 800.0, vs30 >= 360.0)
          f_s[idx] = C["eB"]
          # Site Class C
          idx = np.logical_and(vs30 < 360.0, vs30 >= 180.0)
          f_s[idx] = C["eC"]
          # Site Class D
          idx = vs30 < 180.0
          f_s[idx] = C["eD"]
          return f_s
docs: Returns the site amplification given Eurocode 8 site classification