change_sampled_parameters.py

#!/bin/python
"""
Tutorial to demonstrate running parameter estimation sampling in non-standard parameters for an injected signal.

This example estimates the masses using a uniform prior in chirp mass and mass ratio and distance using a uniform in
comoving volume prior on luminosity distance between luminosity distances of 100Mpc and 5Gpc, the cosmology is WMAP7.
"""
from __future__ import division, print_function
import tupak
import numpy as np


tupak.core.utils.setup_logger(log_level="info")

time_duration = 4.
sampling_frequency = 2048.
outdir = 'outdir'

np.random.seed(151226)

injection_parameters = dict(mass_1=36., mass_2=29., a_1=0.4, a_2=0.3, tilt_1=0.5, tilt_2=1.0, phi_12=1.7, phi_jl=0.3,
                            luminosity_distance=3000., iota=0.4, psi=2.659, phase=1.3, geocent_time=1126259642.413,
                            ra=1.375, dec=-1.2108)

waveform_arguments = dict(waveform_approximant='IMRPhenomPv2',
                          reference_frequency=50.)

# Create the waveform_generator using a LAL BinaryBlackHole source function
waveform_generator = tupak.gw.waveform_generator.WaveformGenerator(
    sampling_frequency=sampling_frequency, time_duration=time_duration,
    frequency_domain_source_model=tupak.gw.source.lal_binary_black_hole,
    parameter_conversion=tupak.gw.conversion.convert_to_lal_binary_black_hole_parameters,
    non_standard_sampling_parameter_keys=['chirp_mass', 'mass_ratio'],
    parameters=injection_parameters, waveform_arguments=waveform_arguments)
hf_signal = waveform_generator.frequency_domain_strain()

# Set up interferometers.
IFOs = [tupak.gw.detector.get_interferometer_with_fake_noise_and_injection(
    name, injection_polarizations=hf_signal, injection_parameters=injection_parameters, time_duration=time_duration,
    sampling_frequency=sampling_frequency, outdir=outdir) for name in ['H1', 'L1', 'V1']]

# Set up prior
priors = tupak.gw.prior.BBHPriorSet()
priors.pop('mass_1')
priors.pop('mass_2')
priors['chirp_mass'] = tupak.prior.Uniform(name='chirp_mass', latex_label='$m_c$', minimum=13, maximum=45)
priors['mass_ratio'] = tupak.prior.Uniform(name='mass_ratio', latex_label='$q$', minimum=0.1, maximum=1)
# These parameters will not be sampled
for key in ['a_1', 'a_2', 'tilt_1', 'tilt_2', 'phi_12', 'phi_jl', 'psi', 'ra', 'dec', 'geocent_time', 'phase']:
    priors[key] = injection_parameters[key]
print(priors)

# Initialise GravitationalWaveTransient
likelihood = tupak.gw.likelihood.GravitationalWaveTransient(interferometers=IFOs, waveform_generator=waveform_generator)

# Run sampler
result = tupak.core.sampler.run_sampler(likelihood=likelihood, priors=priors, sampler='dynesty',
                                        injection_parameters=injection_parameters, label='DifferentParameters',
                                        outdir=outdir, conversion_function=tupak.gw.conversion.generate_all_bbh_parameters)
result.plot_corner()