Closed bilby-bot closed 3 weeks ago
In GitLab by @git.ligo:colm.talbot on Nov 13, 2021, 14:01
Hi @git.ligo:ecm, the standard way to use TD approximants in Bilby
is through SimInspiralFD
which can call any waveform model implemented in lalsimulation
with standardized conditioning/FFT. If you're model is implemented in lalsim
you can just use that interface.
Otherwise, you have two options:
frequency_domain_source_model
to the WaveformGenerator
.time_domain_source_model
to the WaveformGenerator
instead. If you then call waveform_generator.frequency_domain_strain
internally your passed time_domain_source_model
will be called and the returned values will be FFT'd. Note that this doesn't include any tapering so that will have to be implemented by you.In GitLab by @git.ligo:colm.talbot on Nov 29, 2021, 17:44
@git.ligo:ecm did the previous comment help? I don't think there's any issue we can fix here, this is explained in the documentation.
In GitLab by @git.ligo:ecm on Dec 1, 2021, 14:34
Hi @git.ligo:colm.talbot
thank you for the feedback! Yes, this helps. We're going the 2nd option and may come back with other questions.
Cheers, Eric
In GitLab by @git.ligo:ecm on Nov 2, 2021, 17:25
Dear Bilby developers,
I understand that the WaveformGenerator class includes the possibility of a time-domain approximant:
https://git.ligo.org/lscsoft/bilby/-/blob/master/bilby/gw/waveform_generator.py#L35
however GravitationalWaveTransient likelihood object seems to use frequency-domain approximant only:
https://git.ligo.org/lscsoft/bilby/-/blob/master/bilby/gw/likelihood.py#L42
confirmed by the fact that gw.source.lal_binary_black_hole() is a wrapper around lalsim_SimInspiralFD
https://git.ligo.org/lscsoft/bilby/-/blob/master/bilby/gw/source.py#L365
Is this true? Or is Bilby able to produce a frequency-domain strain from time-domain data?
Best, Eric
PS: we're trying to plug-in our own time-domain waveform approximant.