from addict import Dict
import lenstronomy.Util.param_util as param_util
from .base_bnn_prior import BaseBNNPrior
[docs]class DiagonalBNNPrior(BaseBNNPrior):
"""BNN prior with independent parameters
Note
----
This BNNPrior is cosmology-agnostic. For a version that's useful for H0 inference, see `DiagonalCosmoBNNPrior`.
"""
def __init__(self, bnn_omega, components):
"""
Note
----
The dictionary attributes are copies of the config corresponding to each component.
The number of attributes depends on the number of components.
Attributes
----------
components : list
list of components, e.g. `lens_mass`
lens_mass : dict
profile type and parameters of the lens mass
src_light : dict
profile type and parameters of the source light
"""
BaseBNNPrior.__init__(self, bnn_omega, components)
self.params_to_exclude = []
self.set_params_list(self.params_to_exclude)
self.set_comps_qphi_to_e1e2()
[docs] def sample(self):
"""Gets kwargs of sampled parameters to be passed to lenstronomy
Returns
-------
dict
dictionary of config-specified components (e.g. lens mass), itself
a dictionary of sampled parameters corresponding to the config-specified
profile of that component
"""
# Initialize nested dictionary of kwargs
kwargs = Dict()
# Realize samples
for comp, param_name in self.params_to_realize:
hyperparams = getattr(self, comp)[param_name].copy()
kwargs[comp][param_name] = self.sample_param(hyperparams)
# Convert any q, phi into e1, e2 as required by lenstronomy
for comp in self.comps_qphi_to_e1e2: # e.g. 'lens_mass'
q = kwargs[comp].pop('q')
phi = kwargs[comp].pop('phi')
e1, e2 = param_util.phi_q2_ellipticity(phi, q)
kwargs[comp]['e1'] = e1
kwargs[comp]['e2'] = e2
# Source pos is defined wrt the lens pos
kwargs['src_light']['center_x'] += kwargs['lens_mass']['center_x']
kwargs['src_light']['center_y'] += kwargs['lens_mass']['center_y']
# Ext shear is defined wrt the lens center
kwargs['external_shear']['ra_0'] = kwargs['lens_mass']['center_x']
kwargs['external_shear']['dec_0'] = kwargs['lens_mass']['center_y']
if 'lens_light' in self.components:
# Lens light shares center with lens mass
kwargs['lens_light']['center_x'] = kwargs['lens_mass']['center_x']
kwargs['lens_light']['center_y'] = kwargs['lens_mass']['center_y']
return kwargs