# Source code for openquake.hazardlib.scalerel.base

```# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# Copyright (C) 2012-2017 GEM Foundation
#
# OpenQuake 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.
#
# OpenQuake 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 OpenQuake. If not, see <http://www.gnu.org/licenses/>.

"""
Module :mod:`openquake.hazardlib.scalerel.base` defines abstract base
classes for :class:`ASR <BaseASR>`, :class:`MSR <BaseMSR>`,
:class:`ASRSigma <BaseASRSigma>`, and :class:`MSRSigma <BaseMSRSigma>`
"""
import abc
import math
from openquake.baselib.python3compat import with_metaclass

[docs]class BaseASR(with_metaclass(abc.ABCMeta)):
"""
A base class for Area-Magnitude Scaling Relationship.
Allows calculation of rupture magnitude from area.
"""

@abc.abstractmethod
[docs]    def get_median_mag(self, area, rake):
"""
Return median magnitude (Mw) given the area and rake.

:param area:
Area in square km.
:param rake:
Rake angle (the rupture propagation direction) in degrees,
from -180 to 180.
"""

def __repr__(self):
"""
Returns the name of the class
"""
return "<%s>" % self.__class__.__name__

[docs]class BaseASRSigma(with_metaclass(abc.ABCMeta, BaseASR)):
"""
Extend :class:`BaseASR` and allows to include uncertainties (sigma) in
rupture magnitude estimation.
"""

@abc.abstractmethod
[docs]    def get_std_dev_mag(self, rake):
"""
Return the standard deviation on the magnitude.

:param rake:
Rake angle (the rupture propagation direction) in degrees,
from -180 to 180.
"""

[docs]class BaseMSR(with_metaclass(abc.ABCMeta)):
"""
A base class for Magnitude-Area Scaling Relationship.
Allows calculation of rupture area from magnitude.
"""

@abc.abstractmethod
[docs]    def get_median_area(self, mag, rake):
"""
Return median area (in square km) from magnitude ``mag`` and ``rake``.

To be overridden by subclasses.

:param mag:
Moment magnitude (Mw).
:param rake:
Rake angle (the rupture propagation direction) in degrees,
from -180 to 180.
"""

def __repr__(self):
"""
Returns the name of the class
"""
return "<%s>" % self.__class__.__name__

[docs]class BaseMSRSigma(with_metaclass(abc.ABCMeta, BaseMSR)):
"""
Extends :class:`BaseMSR` and allows to include uncertainties (sigma) in
rupture area estimation.
"""

@abc.abstractmethod
[docs]    def get_std_dev_area(self, mag, rake):
"""
Return the standard deviation of the area distribution
given magnitude ``mag`` and rake.

To be overridden by subclasses.

:param mag:
Moment magnitude (Mw).
:param rake:
Rake angle (the rupture propagation direction) in degrees,
from -180 to 180.
"""
```