Source code for openquake.hazardlib.gsim.utils

# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4
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"""
Module :mod:`openquake.hazardlib.gsim.utils` contains functions that are common
to several GMPEs.
"""
import numpy as np


[docs]def mblg_to_mw_johnston_96(mag): """ Convert magnitude value from Mblg to Mw using Johnston 1996 conversion equation. Implements equation as in line 1654 in hazgridXnga2.f """ return 1.14 + 0.24 * mag + 0.0933 * mag * mag
[docs]def mblg_to_mw_atkinson_boore_87(mag): """ Convert magnitude value from Mblg to Mw using Atkinson and Boore 1987 conversion equation. Implements equation as in line 1656 in hazgridXnga2.f """ return 2.715 - 0.277 * mag + 0.127 * mag * mag
[docs]def clip_mean(imt, mean): """ Clip GMPE mean value at 1.5 g for PGA and 3 g for short periods (0.02 < T < 0.55) """ if imt.period == 0: mean[mean > 0.405] = 0.405 if 0.02 < imt.period < 0.55: mean[mean > 1.099] = 1.099 return mean
[docs]def get_fault_type_dummy_variables(ctx): """ Get fault type dummy variables, see Table 2, pag 107. Fault type (Strike-slip, Normal, Thrust/reverse) is derived from rake angle. Rakes angles within 30 of horizontal are strike-slip, angles from 30 to 150 are reverse, and angles from -30 to -150 are normal. See paragraph 'Predictor Variables' pag 103. Note that the 'Unspecified' case is not considered, because rake is always given. """ SS = np.zeros_like(ctx.rake) # strike-slip NS = np.zeros_like(ctx.rake) # normal RS = np.zeros_like(ctx.rake) # reverse SS[(np.abs(ctx.rake) <= 30.) | (180. - np.abs(ctx.rake) <= 30.)] = 1. RS[(ctx.rake > 30.) & (ctx.rake < 150.)] = 1. NS[(ctx.rake > -150.) & (ctx.rake < -30)] = 1. return SS, NS, RS