Commit c3972e15 authored by Gregory Ashton's avatar Gregory Ashton
Browse files

Merge branch 'updating_standard_cbc_examples' into 'master'

created full 15 dimensional parameter space example

See merge request !296
parents 34a62573 2065e11c
Pipeline #44154 passed with stages
in 9 minutes and 46 seconds
......@@ -2,17 +2,22 @@
Compact binary coalescence parameter estimation
In this example, which can be found `here
In `this example
we demonstrate how to generate simulated data for a binary black hole
coalescence observed by the two LIGO interferometers at Hanford and Livingston.
coalescence observed by the two LIGO interferometers at Hanford and Livingston
for all parameters in the `IMRPhenomPv2` waveform model.
.. literalinclude:: /../examples/injection_examples/
The code will take around 15 hours to run.
For testing, you may prefer to run the `4-parameter CBC tutorial
.. literalinclude:: /../examples/injection_examples/
:language: python
Running this script will generate data then perform parameter estimation for
the luminosity distance, masses and inclination angle :math:`\iota`. In doing
Running this script will generate data then perform parameter estimation. In doing
all of this, it prints information about the matched-filter SNRs in each
detector (saved to the log-file). Moreover, it generates a plot for each
detector showing the data, amplitude spectral density (ASD) and the signal;
......@@ -22,6 +27,6 @@ here is an example for the Hanford detector:
Finally, after running the parameter estimation. It generates a corner plot:
.. image:: images/basic_tutorial_corner.png
.. image:: images/full_15_parameters_corner.png
The solid lines indicate the injection parameters.
......@@ -10,8 +10,10 @@ Examples
2. `Examples of injecting and recovering
data <>`__
- `A basic
tutorial <>`__
- `4-parameter CBC
tutorial <>`__
- `15-parameter CBC tutorial
- `Create your own source
model <>`__
- `Create your own time-domain source
#!/usr/bin/env python
Tutorial to demonstrate running parameter estimation on a full 15 parameter
space for an injected cbc signal. This is the standard injection analysis script
one can modify for the study of injected CBC events.
from __future__ import division, print_function
import numpy as np
import bilby
# Set the duration and sampling frequency of the data segment that we're
# going to inject the signal into
duration = 4.
sampling_frequency = 2048.
# Specify the output directory and the name of the simulation.
outdir = 'outdir'
label = 'full_15_parameters'
bilby.core.utils.setup_logger(outdir=outdir, label=label)
# Set up a random seed for result reproducibility. This is optional!
# We are going to inject a binary black hole waveform. We first establish a
# dictionary of parameters that includes all of the different waveform
# parameters, including masses of the two black holes (mass_1, mass_2),
# spins of both black holes (a, tilt, phi), etc.
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=2000., iota=0.4, psi=2.659,
phase=1.3, geocent_time=1126259642.413, ra=1.375, dec=-1.2108)
# Fixed arguments passed into the source model
waveform_arguments = dict(waveform_approximant='IMRPhenomPv2',
reference_frequency=50., minimum_frequency=20.)
# Create the waveform_generator using a LAL BinaryBlackHole source function
# the generator will convert all the parameters
waveform_generator =
duration=duration, sampling_frequency=sampling_frequency,,,
# Set up interferometers. In this case we'll use two interferometers
# (LIGO-Hanford (H1), LIGO-Livingston (L1). These default to their design
# sensitivity
ifos =['H1', 'L1'])
sampling_frequency=sampling_frequency, duration=duration,
start_time=injection_parameters['geocent_time'] - 3)
# For this analysis, we implemenet the standard BBH priors defined, except for
# the definition of the time prior, which is defined as uniform about the
# injected value.
# Furthermore, we decide to sample in chirp mass and mass ratio, due to the
# preferred shape for the associated posterior distributions.
priors =
priors['chirp_mass'] = bilby.prior.Uniform(
name='chirp_mass', latex_label='$M$', minimum=10.0, maximum=100.0,
priors['mass_ratio'] = bilby.prior.Uniform(
name='mass_ratio', latex_label='$q$', minimum=0.5, maximum=1.0)
priors['geocent_time'] = bilby.core.prior.Uniform(
minimum=injection_parameters['geocent_time'] - 0.1,
maximum=injection_parameters['geocent_time'] + 0.1,
name='geocent_time', latex_label='$t_c$', unit='$s$')
# Initialise the likelihood by passing in the interferometer data (ifos) and
# the waveoform generator, as well the priors.
# The explicit time, distance, and phase marginalizations are turned on to
# improve convergence, and the parameters are recovered by the conversion
# function.
likelihood =
interferometers=ifos, waveform_generator=waveform_generator, priors=priors,
distance_marginalization=True, phase_marginalization=True, time_marginalization=True)
# Run sampler. In this case we're going to use the `cpnest` sampler
# Note that the maxmcmc parameter is increased so that between each iteration of
# the nested sampler approach, the walkers will move further using an mcmc
# approach, searching the full parameter space.
# The conversion function will determine the distance, phase and coalescence
# time posteriors in post processing.
result = bilby.run_sampler(
likelihood=likelihood, priors=priors, sampler='cpnest', npoints=2000,
injection_parameters=injection_parameters, outdir=outdir,
label=label, maxmcmc=2000,
# Make a corner plot.
......@@ -43,7 +43,7 @@ class Test(unittest.TestCase):
def test_examples(self):
""" Loop over examples to check they run """
examples = ['examples/injection_examples/',
examples = ['examples/injection_examples/',
......@@ -54,5 +54,3 @@ class Test(unittest.TestCase):
if __name__ == '__main__':
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment