def compute(self, ctx, imts, mean, sig, tau, phi):
"""
See :meth:`superclass method
<.base.GroundShakingIntensityModel.compute>`
for spec of input and result values.
"""
# horrible hack to fix the distance parameters; needed for the can15
# subclasses; extra distances are add in can15.eastern
# this also affects generic_gmpe_avgsa_test.py
vars(ctx).update(contexts.get_dists(ctx))
# compute PGA on rock conditions - needed to compute non-linear
# site amplification term
pga4nl = _get_pga_on_rock(self.COEFFS[PGA()], ctx)
for m, imt in enumerate(imts):
C = self.COEFFS[imt]
C_SR = self.COEFFS_SOIL_RESPONSE[imt]
# equation 1, pag 106, without sigma term, that is only the first 3
# terms. The third term (site amplification) is computed as given
# in equation (6), that is the sum of a linear term - equation (7)
# - and a non-linear one - equations (8a) to (8c).
# Mref, Rref values are given in the caption to table 6, pag 119.
if imt == PGA():
# avoid recomputing PGA on rock, just add site terms
mean[m] = np.log(pga4nl) + \
_get_site_amplification_linear(ctx.vs30, C_SR) + \
_get_site_amplification_non_linear(ctx.vs30, pga4nl, C_SR)
else:
mean[m] = _compute_magnitude_scaling(ctx, C) + \
_compute_distance_scaling(ctx, C) + \
_get_site_amplification_linear(ctx.vs30, C_SR) + \
_get_site_amplification_non_linear(ctx.vs30, pga4nl, C_SR)
if self.kind in ('2011', 'prime'):
# correction factor (see Atkinson and Boore, 2011; equation 5
# at page 1126 and nga08_gm_tmr.for line 508
corr_fact = 10.0**(np.max([0, 3.888 - 0.674 * ctx.mag]) -
(np.max([0, 2.933 - 0.510 * ctx.mag]) *
np.log10(ctx.rjb + 10.)))
mean[m] = np.log(np.exp(mean[m]) * corr_fact)
if self.kind == 'hawaii':
hawaii_adjust(mean[m], ctx, imt)
elif self.kind == 'prime':
# Implements the Boore & Atkinson (2011) adjustment to the
# Atkinson (2008) GMPE
A08 = self.COEFFS_A08[imt]
f_ena = 10.0 ** (A08["c"] + A08["d"] * ctx.rjb)
mean[m] = np.log(np.exp(mean[m]) * f_ena)
set_sig(self.kind, C, sig[m], tau[m], phi[m])
def get_mean_and_stddevs(self, sites, rup, dists, imt, stddev_types):
"""
See :meth:`superclass method
<.base.GroundShakingIntensityModel.get_mean_and_stddevs>`
for spec of input and result values.
"""
# extracting dictionary of coefficients specific to required
# intensity measure type.
C = self.COEFFS[imt]
C_SR = self.COEFFS_SOIL_RESPONSE[imt]
# compute PGA on rock conditions - needed to compute non-linear
# site amplification term
vars(rup).update(contexts.get_dists(dists)) # update distances
pga4nl = self._get_pga_on_rock(rup, C)
# equation 1, pag 106, without sigma term, that is only the first 3
# terms. The third term (site amplification) is computed as given in
# equation (6), that is the sum of a linear term - equation (7) - and
# a non-linear one - equations (8a) to (8c).
# Mref, Rref values are given in the caption to table 6, pag 119.
if imt == PGA():
# avoid recomputing PGA on rock, just add site terms
mean = np.log(pga4nl) + \
self._get_site_amplification_linear(sites.vs30, C_SR) + \
self._get_site_amplification_non_linear(sites.vs30, pga4nl,
C_SR)
else:
mean = self._compute_magnitude_scaling(rup, C) + \
self._compute_distance_scaling(rup, C) + \
self._get_site_amplification_linear(sites.vs30, C_SR) + \
self._get_site_amplification_non_linear(sites.vs30, pga4nl,
C_SR)
stddevs = self._get_stddevs(C, stddev_types, len(sites.vs30))
return mean, stddevs