gw.transforms.gnpe_transforms.GNPECoalescenceTimes

gw.transforms.gnpe_transforms.GNPECoalescenceTimes(
    ifo_list,
    kernel,
    exact_global_equivariance=True,
    inference=False,
)

GNPE 1 Transformation for detector coalescence times.

For each of the detector coalescence times, a proxy is generated by adding a perturbation epsilon from the GNPE kernel to the true detector time. This proxy is subtracted from the detector time, such that the overall time shift only amounts to -epsilon in training. This standardizes the input data to the inference network, since the applied time shifts are always restricted to the range of the kernel.

To preserve information at inference time, conditioning of the inference network on the proxies is required. To that end, the proxies are stored in sample[ ‘gnpe_proxies’].

We can enforce an exact equivariance under global time translations, by subtracting one proxy (by convention: the first one, usually for H1 ifo) from all other proxies, and from the geocent time, see 1. This is enabled with the flag exact_global_equivariance.

Note that this transform does not modify the data itself. It only determines the amount by which to time-shift the data.

Parameters

Name	Type	Description	Default
ifo_list	bilby.gw.detector.InterferometerList	List of interferometers.	required
kernel	str	Defines a Bilby prior, to be used for all interferometers.	required
exact_global_equivariance	bool = True	Whether to impose the exact global time translation symmetry.	True
inference	bool = False	Whether to use inference or training mode.	False

Attributes

Name	Description
context_parameters
exact_global_equivariance
ifo_time_labels
inference