from lenstronomy.LensModel.lens_model import LensModel
from lenstronomy.LightModel.light_model import LightModel
from lenstronomy.PointSource.point_source import PointSource
from astropy.cosmology import default_cosmology
from lenstronomy.Cosmo.lens_cosmo import LensCosmo
import copy
__all__ = ["ModelAPI"]
[docs]
class ModelAPI(object):
"""This class manages the model choices.
The role is to return instances of the lenstronomy LightModel, LensModel,
PointSource modules according to the options chosen by the user. Currently, all
other model choices are equivalent to the ones provided by LightModel, LensModel,
PointSource. The current options of the class instance only describe a subset of
possibilities.
"""
[docs]
def __init__(
self,
lens_model_list=None,
z_lens=None,
z_source=None,
lens_redshift_list=None,
source_light_model_list=None,
lens_light_model_list=None,
point_source_model_list=None,
source_redshift_list=None,
cosmo=None,
z_source_convention=None,
tabulated_deflection_angles=None,
observed_convention_index=None,
):
"""# TODO: make inputs follow the kwargs_model of the class_creator instances of
'kwargs_model', # i.e. multi-plane options, perhaps others
:param lens_model_list: list of strings with lens model names
:param z_lens: redshift of the deflector (only considered when operating in
single plane mode). Is only needed for specific functions that require a
cosmology.
:param z_source: redshift of the source: Needed in multi_plane option only, not
required for the core functionalities in the single plane mode. This will be
the redshift of the source plane (if not further specified the
'source_redshift_list') and the point source redshift (regardless of
'source_redshift_list')
:param lens_redshift_list: list of deflector redshift (corresponding to the lens
model list), only applicable in multi_plane mode.
:param source_light_model_list: list of strings with source light model names
(lensed light profiles)
:param lens_light_model_list: list of strings with lens light model names (not
lensed light profiles)
:param point_source_model_list: list of strings with point source model names
:param source_redshift_list: list of redshifts of the source profiles (optional)
:param cosmo: instance of the astropy cosmology class. If not specified, uses
the default cosmology.
:param z_source_convention: float, redshift of a source to define the reduced
deflection angles of the lens models. If None, 'z_source' is used.
:param tabulated_deflection_angles: a class that returns deflection angles given
a set of (x, y) coordinates. Effectively a fixed lens model. See
documentation in Profiles.numerical_alpha
:param observed_convention_index: a list of indices that correspond to lens
models where the center_x,center_y values correspond to the observed (lensed
positions), not the physical positions in space
"""
if lens_model_list is None:
lens_model_list = []
if source_light_model_list is None:
source_light_model_list = []
if lens_light_model_list is None:
lens_light_model_list = []
if point_source_model_list is None:
point_source_model_list = []
if cosmo is None:
cosmo = default_cosmology.get()
# making sure multi_plane mode is activated when either lens or source redshift lists are provided
if lens_redshift_list is not None or source_redshift_list is not None:
multi_plane = True
else:
multi_plane = False
if z_source_convention is None:
z_source_convention = z_source
self._lens_model_class = LensModel(
lens_model_list=lens_model_list,
z_source=z_source,
z_lens=z_lens,
lens_redshift_list=lens_redshift_list,
multi_plane=multi_plane,
cosmo=cosmo,
z_source_convention=z_source_convention,
numerical_alpha_class=tabulated_deflection_angles,
observed_convention_index=observed_convention_index,
)
self._source_model_class = LightModel(
light_model_list=source_light_model_list,
source_redshift_list=source_redshift_list,
)
self._lens_light_model_class = LightModel(
light_model_list=lens_light_model_list
)
fixed_magnification = [False] * len(point_source_model_list)
for i, ps_type in enumerate(point_source_model_list):
if ps_type == "SOURCE_POSITION":
fixed_magnification[i] = True
self._point_source_model_class = PointSource(
point_source_type_list=point_source_model_list,
lens_model=self._lens_model_class,
fixed_magnification_list=fixed_magnification,
)
self._cosmo = cosmo
self._z_source_convention = z_source_convention
self._lens_redshift_list = lens_redshift_list
self._z_lens = z_lens
@property
def lens_model_class(self):
"""
:return: instance of lenstronomy LensModel class
"""
return self._lens_model_class
@property
def lens_light_model_class(self):
"""
:return: instance of lenstronomy LightModel class describing the non-lensed light profiles
"""
return self._lens_light_model_class
@property
def source_model_class(self):
"""
:return: instance of lenstronomy LightModel class describing the source light profiles
"""
return self._source_model_class
@property
def point_source_model_class(self):
"""
:return: instance of lenstronomy PointSource class describing the point sources (lensed and unlensed)
"""
return self._point_source_model_class
[docs]
def physical2lensing_conversion(self, kwargs_mass):
"""
:param kwargs_mass: list of keyword arguments of all the lens models. Einstein radius 'theta_E' are replaced by
'sigma_v', velocity dispersion in km/s, 'alpha_Rs' and 'Rs' of NFW profiles are replaced by 'M200' and
'concentration'
:return: kwargs_lens in reduced deflection angles compatible with the `LensModel` instance of this module
"""
kwargs_lens = copy.deepcopy(kwargs_mass)
for i in range(len(kwargs_mass)):
kwargs_mass_i = kwargs_mass[i]
if self._lens_redshift_list is None:
z_lens = self._z_lens
else:
z_lens = self._lens_redshift_list[i]
lens_cosmo = LensCosmo(z_lens, self._z_source_convention, cosmo=self._cosmo)
if "sigma_v" in kwargs_mass_i:
sigma_v = kwargs_mass_i["sigma_v"]
theta_E = lens_cosmo.sis_sigma_v2theta_E(sigma_v)
kwargs_lens[i]["theta_E"] = theta_E
del kwargs_lens[i]["sigma_v"]
elif "M200" in kwargs_mass_i:
M200 = kwargs_mass_i["M200"]
c = kwargs_mass_i["concentration"]
Rs, alpha_RS = lens_cosmo.nfw_physical2angle(M200, c)
kwargs_lens[i]["Rs"] = Rs
kwargs_lens[i]["alpha_Rs"] = alpha_RS
del kwargs_lens[i]["M200"]
del kwargs_lens[i]["concentration"]
return kwargs_lens