# coding: utf-8
# The Hazard Library
# Copyright (C) 2012-2014, GEM Foundation
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
"""
:mod:`openquake.hazardlib.calc.hazard_curve` implements
:func:`hazard_curves`.
"""
import sys
import time
import collections
import numpy
from openquake.baselib.python3compat import range, raise_
from openquake.baselib.performance import DummyMonitor
from openquake.hazardlib.calc import filters
from openquake.hazardlib.gsim.base import ContextMaker, FarAwayRupture
from openquake.hazardlib.imt import from_string
from openquake.baselib.general import deprecated
[docs]def zero_curves(num_sites, imtls):
"""
:param num_sites: the number of sites
:param imtls: the intensity measure levels dictionary
:returns: an array of zero curves with length num_sites
"""
# numpy dtype for the hazard curves
imt_dt = numpy.dtype([(imt, float, 1 if imls is None else len(imls))
for imt, imls in imtls.items()])
zero = numpy.zeros(num_sites, imt_dt)
return zero
[docs]def zero_maps(num_sites, imts):
"""
:param num_sites: the number of sites
:param imts: the intensity measure types
:returns: an array of zero curves with length num_sites
"""
# numpy dtype for the hazard maps
imt_dt = numpy.dtype([(imt, float) for imt in imts])
zero = numpy.zeros(num_sites, imt_dt)
return zero
[docs]def agg_curves(acc, curves):
"""
Aggregate hazard curves by composing the probabilities.
:param acc: an accumulator array
:param curves: an array of hazard curves
:returns: a new accumulator
"""
new = numpy.array(acc) # copy of the accumulator
for imt in curves.dtype.fields:
new[imt] = 1. - (1. - curves[imt]) * (1. - acc[imt])
return new
@deprecated('Use calc_hazard_curves instead')
[docs]def hazard_curves(
sources, sites, imtls, gsim_by_trt, truncation_level=None,
source_site_filter=filters.source_site_noop_filter,
rupture_site_filter=filters.rupture_site_noop_filter):
"""
Deprecated. It does the same job of
:func:`openquake.hazardlib.calc.hazard_curve.calc_hazard_curves`,
with the only difference that the intensity measure types in input
and output are hazardlib objects instead of simple strings.
"""
imtls = {str(imt): imls for imt, imls in imtls.items()}
curves_by_imt = calc_hazard_curves(
sources, sites, imtls, gsim_by_trt, truncation_level,
source_site_filter=filters.source_site_noop_filter,
rupture_site_filter=filters.rupture_site_noop_filter)
return {from_string(imt): curves_by_imt[imt] for imt in imtls}
[docs]def calc_hazard_curves(
sources, sites, imtls, gsim_by_trt, truncation_level=None,
source_site_filter=filters.source_site_noop_filter,
rupture_site_filter=filters.rupture_site_noop_filter,
maximum_distance=None):
"""
Compute hazard curves on a list of sites, given a set of seismic sources
and a set of ground shaking intensity models (one per tectonic region type
considered in the seismic sources).
Probability of ground motion exceedance is computed using the following
formula ::
P(X≥x|T) = 1 - ∏ ∏ Prup_ij(X<x|T)
where ``P(X≥x|T)`` is the probability that the ground motion parameter
``X`` is exceeding level ``x`` one or more times in a time span ``T``, and
``Prup_ij(X<x|T)`` is the probability that the j-th rupture of the i-th
source is not producing any ground motion exceedance in time span ``T``.
The first product ``∏`` is done over sources, while the second one is done
over ruptures in a source.
The above formula computes the probability of having at least one ground
motion exceedance in a time span as 1 minus the probability that none of
the ruptures in none of the sources is causing a ground motion exceedance
in the same time span. The basic assumption is that seismic sources are
independent, and ruptures in a seismic source are also independent.
:param sources:
A sequence of seismic sources objects (instances of subclasses
of :class:`~openquake.hazardlib.source.base.BaseSeismicSource`).
:param sites:
Instance of :class:`~openquake.hazardlib.site.SiteCollection` object,
representing sites of interest.
:param imtls:
Dictionary mapping intensity measure type strings
to lists of intensity measure levels.
:param gsim_by_trt:
Dictionary mapping tectonic region types (members
of :class:`openquake.hazardlib.const.TRT`) to
:class:`~openquake.hazardlib.gsim.base.GMPE` or
:class:`~openquake.hazardlib.gsim.base.IPE` objects.
:param truncation_level:
Float, number of standard deviations for truncation of the intensity
distribution.
:param source_site_filter:
Optional source-site filter function. See
:mod:`openquake.hazardlib.calc.filters`.
:param rupture_site_filter:
Optional rupture-site filter function. See
:mod:`openquake.hazardlib.calc.filters`.
:returns:
An array of size N, where N is the number of sites, which elements
are records with fields given by the intensity measure types; the
size of each field is given by the number of levels in ``imtls``.
"""
sources_by_trt = collections.defaultdict(list)
for src in sources:
sources_by_trt[src.tectonic_region_type].append(src)
curves = zero_curves(len(sites), imtls)
for trt in sources_by_trt:
curves = agg_curves(curves, hazard_curves_per_trt(
sources_by_trt[trt], sites, imtls, [gsim_by_trt[trt]],
truncation_level, source_site_filter, rupture_site_filter)[0])
return curves
# TODO: remove the rupture_site_filter, since its work is now done by the
# maximum_distance parameter; see what would break
[docs]def hazard_curves_per_trt(
sources, sites, imtls, gsims, truncation_level=None,
source_site_filter=filters.source_site_noop_filter,
rupture_site_filter=filters.rupture_site_noop_filter,
maximum_distance=None, monitor=DummyMonitor()):
"""
Compute the hazard curves for a set of sources belonging to the same
tectonic region type for all the GSIMs associated to that TRT.
The arguments are the same as in :func:`calc_hazard_curves`, except
for ``gsims``, which is a list of GSIM instances.
:returns:
A list of G arrays of size N, where N is the number of sites and
G the number of gsims. Each array contains records with fields given
by the intensity measure types; the size of each field is given by the
number of levels in ``imtls``.
"""
cmaker = ContextMaker(gsims, maximum_distance)
gnames = list(map(str, gsims))
imt_dt = numpy.dtype([(imt, float, len(imtls[imt]))
for imt in sorted(imtls)])
imts = {from_string(imt): imls for imt, imls in imtls.items()}
curves = [numpy.ones(len(sites), imt_dt) for gname in gnames]
sources_sites = ((source, sites) for source in sources)
ctx_mon = monitor('making contexts', measuremem=False)
rup_mon = monitor('getting ruptures', measuremem=False)
pne_mon = monitor('computing poes', measuremem=False)
monitor.calc_times = [] # pairs (src_id, delta_t)
for source, s_sites in source_site_filter(sources_sites):
t0 = time.time()
try:
with rup_mon:
rupture_sites = list(rupture_site_filter(
(rupture, s_sites) for rupture in source.iter_ruptures()))
for rupture, r_sites in rupture_sites:
with ctx_mon:
try:
sctx, rctx, dctx = cmaker.make_contexts(
r_sites, rupture)
except FarAwayRupture:
continue
for i, gsim in enumerate(gsims):
with pne_mon:
for imt in imts:
poes = gsim.get_poes(
sctx, rctx, dctx, imt, imts[imt],
truncation_level)
pno = rupture.get_probability_no_exceedance(poes)
expanded_pno = sctx.sites.expand(pno, 1.0)
curves[i][str(imt)] *= expanded_pno
except Exception as err:
etype, err, tb = sys.exc_info()
msg = 'An error occurred with source id=%s. Error: %s'
msg %= (source.source_id, str(err))
raise_(etype, msg, tb)
# we are attaching the calculation times to the monitor
# so that oq-lite (and the engine) can store them
monitor.calc_times.append((source.id, time.time() - t0))
# NB: source.id is an integer; it should not be confused
# with source.source_id, which is a string
for i in range(len(gnames)):
for imt in imtls:
curves[i][imt] = 1. - curves[i][imt]
return curves