def get_site_amplification(self, C, sites):
        """
        Returns the site amplification term
        """
        # Gets delta normalised z1
        dz1 = sites.z1pt0 - np.exp(self._get_lnmu_z1(sites.vs30))
        f_s = C["c5"] * dz1
        # Calculates site amplification term
        f_s[dz1 > self.CONSTANTS["dz1ref"]] = (C["c5"] *
                                               self.CONSTANTS["dz1ref"])
        idx = sites.vs30 > self.CONSTANTS["v1"]
        f_s[idx] += (C["c4"] * np.log(self.CONSTANTS["v1"] / C["vref"]))
        idx = np.logical_not(idx)
        f_s[idx] += (C["c4"] * np.log(sites.vs30[idx] / C["vref"]))
        return f_s
def get_site_amplification ( self , C , sites ) : dz1 = sites . z1pt0 - np . exp ( self . _get_lnmu_z1 ( sites . vs30 ) ) f_s = C [ "c5" ] * dz1 f_s [ dz1 > self . CONSTANTS [ "dz1ref" ] ] = ( C [ "c5" ] * self . CONSTANTS [ "dz1ref" ] ) idx = sites . vs30 > self . CONSTANTS [ "v1" ] f_s [ idx ] += ( C [ "c4" ] * np . log ( self . CONSTANTS [ "v1" ] / C [ "vref" ] ) ) idx = np . logical_not ( idx ) f_s [ idx ] += ( C [ "c4" ] * np . log ( sites . vs30 [ idx ] / C [ "vref" ] ) ) return f_s
Returns the site amplification term