cogwheel.gw_prior.extrinsic.UniformPhasePrior

class cogwheel.gw_prior.extrinsic.UniformPhasePrior(*, tgps, ref_det_name, f_avg, par_dic_0=None, **kwargs)

Bases: ReferenceDetectorMixin, UniformPriorMixin, UnitJacobianMixin, Prior

Uniform prior for the orbital phase.

The sampled variable phi_ref_hat differs from the standard coalescence phase phi_ref by an additive function of psi, iota, ra, dec, time, such that it describes the well-measured phase of the waveform at a reference detector. Note: for waveforms with higher modes the posterior will have a discontinuity when angle(geometric_factor_refdet) = pi. However the folded posterior does not have this discontinuity.

Methods

fplus_fcross_refdet	Antenna coefficients (F+, Fx) at the reference detector.
generate_random_samples	Sample the prior using rejection sampling.
geometric_factor_refdet	Return the complex geometric factor
get_fast_sampled_params	Return a list of parameter names that map to given "fast" standard parameters.
get_init_dict	Return dictionary with keyword arguments to __init__.
get_module_name	Name of the module that defines the instance's class.
init_parameters	Return parameters accepted by the class constructor.
inverse_transform	phi_ref to phi_ref_hat
inverse_transform_samples	Add columns in-place for self.sampled_params to samples.
ln_jacobian_determinant	Natural log Jacobian determinant of the inverse transform.
lnprior	Natural logarithm of the prior probability density.
lnprior_and_transform	Return log prior and standard parameters.
reinstantiate	Return a new instance of the class, possibly updating init_kwargs.
standard_lnprior	Log prior density in standard coordinates.
time_delay_refdet	Time delay from Earth center to the reference detector.
to_json	Write class instance to json file.
transform	phi_ref_hat to phi_ref.
transform_samples	Add columns in-place for self.standard_params to samples.
unfold_apply	Return a function that unfolds its parameters and applies func to each unfolding.

Attributes

conditioned_on
folded_params
folded_reflected_params
folded_shifted_params
max_lnprior	Maximum log prior density, useful for rejection sampling.
periodic_params
range_dic
ref_det_location	3d location of the reference detector on Earth [meters].
reflective_params
sampled_params
standard_params
subclass_registry

fplus_fcross_refdet(ra, dec, psi)

Antenna coefficients (F+, Fx) at the reference detector.

generate_random_samples(n_samples, seed=None, return_lnz=False)

Sample the prior using rejection sampling.

This is more efficient for more uniform priors.

Parameters:

n_samplesint

How many samples to generate.

seed

Passed to numpy.default_rng, for reproducibility.

Returns:

samplespd.DataFrame

Columns are .sampled_params + .standard_params, and rows are samples distributed according to the prior.

lnz, dlnzfloat, float

Log of the integral of the prior over the bounds, and estimate of the 1-sigma uncertainty. Only returned if return_lnz is set to True. Useful for estimating the normalization constant of the prior. Note: This differs from the lnz that nested samplers (e.g. PyMultiNest or Nautilus) would compute, in that it has the phase-space volume differential applied. I.e. if lnprior == 0, lnz == log(prod(self.cubesize)) while nested samplers would return lnz == 0.

geometric_factor_refdet(ra, dec, psi, iota)

Return the complex geometric factor

\[R = \frac{1+\cos^2 \iota}{2} F_{+} - i \cos \iota \ F_{\times}\]

that relates a waveform with generic orientation to an overhead face-on one for quadrupolar waveforms. Note that the amplitude |R| is between 0 and 1.

classmethod get_fast_sampled_params(fast_standard_params)

Return a list of parameter names that map to given “fast” standard parameters.

Useful for sampling fast-slow parameters. Updating fast sampling parameters is guaranteed to only change fast standard parameters.

get_init_dict(**kwargs)

Return dictionary with keyword arguments to __init__.

Only works if the class stores its init parameters as attributes with the same names. Otherwise, the subclass should override this method.

Parameters:

**kwargs

Allows to manually override some keys. The remaining ones will be read from the instance’s attributes. All keywords must be in the __init__ signature. It’s mostly here to facilitate overriding by subclasses.

get_module_name()

Name of the module that defines the instance’s class.

classmethod init_parameters(include_optional=True)

Return parameters accepted by the class constructor.

The parameters are sorted by parameter kind (i.e. positional arguments first, keyword arguments last). The self parameter is excluded.

Parameters:

include_optionalbool

Whether to include parameters with defaults in the returned list.

Returns:

list of inspect.Parameter objects

inverse_transform(phi_ref, iota, ra, dec, psi, t_geocenter)

phi_ref to phi_ref_hat

inverse_transform_samples(samples: DataFrame)

Add columns in-place for self.sampled_params to samples.

Parameters:

samplespandas.Dataframe

Must include columns for .standard_params and .conditioned_on.

Raises:

ValueError

If samples.index is not a simple range.

ln_jacobian_determinant(*par_vals, **par_dic)

Natural log Jacobian determinant of the inverse transform.

Take .standard_params + .conditioned_on parameters and return a float representing

log|∂{sampled_params} / ∂{standard_params}|

lnprior(*par_vals, **par_dic)

Natural logarithm of the prior probability density.

Parameters:

*par_vals, **par_dic

.sampled_params + .conditioned_on parameters

Returns:

float

Natural logarithm of the prior probability density in the space of sampled parameters.

lnprior_and_transform(*par_vals, **par_dic)

Return log prior and standard parameters.

The reason for this function is that for CombinedPrior it is already necessary to evaluate self.transform() in order to evaluate self.lnprior(). CombinedPrior overwrites this function so the user can get both lnprior and transform without evaluating transform twice.

Returns:

float

Log prior, output of .lnprior.

dict

Standard parameters, output of .transform.

property max_lnprior

Maximum log prior density, useful for rejection sampling.

property ref_det_location

3d location of the reference detector on Earth [meters].

reinstantiate(**new_init_kwargs)

Return a new instance of the class, possibly updating init_kwargs.

Values not passed will be taken from the current instance.

standard_lnprior(**parameters)

Log prior density in standard coordinates.

Parameters:

**parameters

Values for .standard_params and .conditioned_on parameters.

time_delay_refdet(ra, dec)

Time delay from Earth center to the reference detector.

to_json(dirname, basename=None, *, dir_permissions=493, file_permissions=420, overwrite=False)

Write class instance to json file.

It can then be loaded with read_json.

transform(phi_ref_hat, iota, ra, dec, psi, t_geocenter)

phi_ref_hat to phi_ref.

transform_samples(samples: DataFrame)

Add columns in-place for self.standard_params to samples.

Parameters:

samplespandas.Dataframe

Must include columns for .sampled_params and .conditioned_on.

Raises:

ValueError

If samples.index is not a simple range.

unfold_apply(func, otypes=(<class 'float'>, ))

Return a function that unfolds its parameters and applies func to each unfolding.

The returned function returns a list of length 2**n_folds.

Parameters:

funccallable

A python function or method.

otypesstr or list of dtypes

Output type, passed to np.vectorize. You can pass None to decide automatically, but then an extra function call will be made.

Returns:

callable

Unfolding function.