diff --git a/bilby/gw/detector/interferometer.py b/bilby/gw/detector/interferometer.py
index b017f36d8e7eebdc47648ddf3dfe22baf9a0d6f9..874d213dfcbefc87abe1a22e4341a5b2d4838989 100644
--- a/bilby/gw/detector/interferometer.py
+++ b/bilby/gw/detector/interferometer.py
@@ -9,6 +9,7 @@ from .. import utils as gwutils
from .calibration import Recalibrate
from .geometry import InterferometerGeometry
from .strain_data import InterferometerStrainData
+from ..conversion import generate_all_bbh_parameters
class Interferometer(object):
@@ -318,8 +319,50 @@ class Interferometer(object):
return signal_ifo
+ def check_signal_duration(self, parameters, raise_error=True):
+ """ Check that the signal with the given parameters fits in the data
+
+ Parameters
+ ==========
+ parameters: dict
+ A dictionary of the injection parameters
+ raise_error: bool
+ If True, raise an error in the signal does not fit. Otherwise, print
+ a warning message.
+ """
+ try:
+ parameters = generate_all_bbh_parameters(parameters)
+ except AttributeError:
+ logger.debug(
+ "generate_all_bbh_parameters parameters failed during check_signal_duration"
+ )
+ return
+
+ if ("mass_1" not in parameters) and ("mass_2" not in parameters):
+ if raise_error:
+ raise AttributeError("Unable to check signal duration as mass not given")
+ else:
+ return
+
+ # Calculate the time to merger
+ deltaT = gwutils.calculate_time_to_merger(
+ frequency=self.minimum_frequency,
+ mass_1=parameters["mass_1"],
+ mass_2=parameters["mass_2"],
+ )
+ deltaT = np.round(deltaT, 1)
+ if deltaT > self.duration:
+ msg = (
+ f"The injected signal has a duration in-band of {deltaT}s, but "
+ f"the data for detector {self.name} has a duration of {self.duration}s"
+ )
+ if raise_error:
+ raise ValueError(msg)
+ else:
+ logger.warning(msg)
+
def inject_signal(self, parameters, injection_polarizations=None,
- waveform_generator=None):
+ waveform_generator=None, raise_error=True):
""" General signal injection method.
Provide the injection parameters and either the injection polarizations
or the waveform generator to inject a signal into the detector.
@@ -337,6 +380,10 @@ class Interferometer(object):
waveform_generator: bilby.gw.waveform_generator.WaveformGenerator, optional
A WaveformGenerator instance using the source model to inject. If
`injection_polarizations` is given, this will be ignored.
+ raise_error: bool
+ If true, raise an error if the injected signal has a duration
+ longer than the data duration. If False, a warning will be printed
+ instead.
Notes
=====
@@ -351,6 +398,8 @@ class Interferometer(object):
if it was passed in. Otherwise it is the return value of waveform_generator.frequency_domain_strain().
"""
+ self.check_signal_duration(parameters, raise_error)
+
if injection_polarizations is None and waveform_generator is None:
raise ValueError(
"inject_signal needs one of waveform_generator or "
diff --git a/bilby/gw/prior.py b/bilby/gw/prior.py
index d88bc23d0051fbe3cae9511829a9202f35ab44c5..7f63d91ee2ebf79fff874b46479822f161e499c2 100644
--- a/bilby/gw/prior.py
+++ b/bilby/gw/prior.py
@@ -17,10 +17,12 @@ from .conversion import (
convert_to_lal_binary_black_hole_parameters,
convert_to_lal_binary_neutron_star_parameters, generate_mass_parameters,
generate_tidal_parameters, fill_from_fixed_priors,
+ generate_all_bbh_parameters,
chirp_mass_and_mass_ratio_to_total_mass,
total_mass_and_mass_ratio_to_component_masses)
from .cosmology import get_cosmology
from .source import PARAMETER_SETS
+from .utils import calculate_time_to_merger
DEFAULT_PRIOR_DIR = os.path.join(os.path.dirname(__file__), 'prior_files')
@@ -683,6 +685,42 @@ class CBCPriorDict(ConditionalPriorDict):
""" Return true if priors include phase parameters """
return self.is_nonempty_intersection("phase")
+ def validate_prior(self, duration, minimum_frequency, N=1000, error=True, warning=False):
+ """ Validate the prior is suitable for use
+
+ Parameters
+ ==========
+ duration: float
+ The data duration in seconds
+ minimum_frequency: float
+ The minimum frequency in Hz of the analysis
+ N: int
+ The number of samples to draw when checking
+ """
+ samples = self.sample(N)
+ samples = generate_all_bbh_parameters(samples)
+ deltaT = np.array([
+ calculate_time_to_merger(
+ frequency=minimum_frequency,
+ mass_1=mass_1,
+ mass_2=mass_2,
+ )
+ for (mass_1, mass_2) in zip(samples["mass_1"], samples["mass_2"])
+ ])
+ if np.all(deltaT < duration):
+ return True
+ if warning:
+ logger.warning(
+ "Prior contains regions of parameter space in which the signal"
+ f" is longer than the data duration {duration}s"
+ )
+ return False
+ if error:
+ raise ValueError(
+ "Prior contains regions of parameter space in which the signal"
+ f" is longer than the data duration {duration}s"
+ )
+
class BBHPriorDict(CBCPriorDict):
def __init__(self, dictionary=None, filename=None, aligned_spin=False,
diff --git a/bilby/gw/utils.py b/bilby/gw/utils.py
index 8f8aeb0354a5914cb31a54faba2357852aaafcd1..a52bfd663e7ed58e07b6ceda3f947414925c4918 100644
--- a/bilby/gw/utils.py
+++ b/bilby/gw/utils.py
@@ -10,6 +10,7 @@ from ..core.utils import (ra_dec_to_theta_phi,
speed_of_light, logger, run_commandline,
check_directory_exists_and_if_not_mkdir,
SamplesSummary, theta_phi_to_ra_dec)
+from ..core.utils.constants import solar_mass
def asd_from_freq_series(freq_data, df):
@@ -1006,3 +1007,37 @@ def ln_i0(value):
The natural logarithm of the bessel function
"""
return np.log(i0e(value)) + value
+
+
+def calculate_time_to_merger(frequency, mass_1, mass_2, chi=0, safety=1.1):
+ """ Leading-order calculation of the time to merger from frequency
+
+ This uses the XLALSimInspiralTaylorF2ReducedSpinChirpTime routine to
+ estimate the time to merger. Based on the implementation in
+ `pycbc.pnutils._get_imr_duration`.
+
+ Parameters
+ ==========
+ frequency: float
+ The frequency (Hz) of the signal from which to calculate the time to merger
+ mass_1, mass_2: float
+ The detector frame component masses
+ chi: float
+ Dimensionless aligned-spin param
+ safety:
+ Multiplicitive safety factor
+
+ Returns
+ =======
+ time_to_merger: float
+ The time to merger from frequency in seconds
+ """
+
+ import lalsimulation
+ return safety * lalsimulation.SimInspiralTaylorF2ReducedSpinChirpTime(
+ frequency,
+ mass_1 * solar_mass,
+ mass_2 * solar_mass,
+ chi,
+ -1
+ )
diff --git a/examples/gw_examples/injection_examples/fast_tutorial.py b/examples/gw_examples/injection_examples/fast_tutorial.py
index 0f40818cc86b2fa7d3a647ca9930e596a03ecf4b..3a2e18fc135b6225e369e28643d5749d0b9db50d 100644
--- a/examples/gw_examples/injection_examples/fast_tutorial.py
+++ b/examples/gw_examples/injection_examples/fast_tutorial.py
@@ -15,6 +15,7 @@ import bilby
# going to inject the signal into
duration = 4.
sampling_frequency = 2048.
+minimum_frequency = 20
# Specify the output directory and the name of the simulation.
outdir = 'outdir'
@@ -35,7 +36,8 @@ injection_parameters = dict(
# Fixed arguments passed into the source model
waveform_arguments = dict(waveform_approximant='IMRPhenomPv2',
- reference_frequency=50., minimum_frequency=20.)
+ reference_frequency=50.,
+ minimum_frequency=minimum_frequency)
# Create the waveform_generator using a LAL BinaryBlackHole source function
waveform_generator = bilby.gw.WaveformGenerator(
@@ -66,13 +68,16 @@ ifos.inject_signal(waveform_generator=waveform_generator,
# sampler. If we do nothing, then the default priors get used.
priors = bilby.gw.prior.BBHPriorDict()
priors['geocent_time'] = bilby.core.prior.Uniform(
- minimum=injection_parameters['geocent_time'] - 1,
- maximum=injection_parameters['geocent_time'] + 1,
+ minimum=injection_parameters['geocent_time'] - 0.1,
+ maximum=injection_parameters['geocent_time'] + 0.1,
name='geocent_time', latex_label='$t_c$', unit='$s$')
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]
+# Perform a check that the prior does not extend to a parameter space longer than the data
+priors.validate_prior(duration, minimum_frequency)
+
# Initialise the likelihood by passing in the interferometer data (ifos) and
# the waveform generator
likelihood = bilby.gw.GravitationalWaveTransient(
diff --git a/test/gw/detector/interferometer_test.py b/test/gw/detector/interferometer_test.py
index d204d6cbc719ff87279b9828a57d199ae74232b8..b01b57e17fe2a1562546c24e8f0fa28e84aebe47 100644
--- a/test/gw/detector/interferometer_test.py
+++ b/test/gw/detector/interferometer_test.py
@@ -61,7 +61,10 @@ class TestInterferometer(unittest.TestCase):
self.waveform_generator.frequency_domain_strain = (
lambda _: self.wg_polarizations
)
- self.parameters = dict(ra=0.0, dec=0.0, geocent_time=0.0, psi=0.0)
+ self.parameters = dict(
+ ra=0.0, dec=0.0, geocent_time=0.0, psi=0.0,
+ mass_1=100, mass_2=100
+ )
bilby.core.utils.check_directory_exists_and_if_not_mkdir(self.outdir)