lenstronomy.PointSource package

Submodules

lenstronomy.PointSource.point_source module

class lenstronomy.PointSource.point_source.PointSource(point_source_type_list, lensModel=None, fixed_magnification_list=None, additional_images_list=None, flux_from_point_source_list=None, magnification_limit=None, save_cache=False, kwargs_lens_eqn_solver=None)[source]

Bases: object

check_image_positions(kwargs_ps, kwargs_lens, tolerance=0.001)[source]

checks whether the point sources in kwargs_ps satisfy the lens equation with a tolerance (computed by ray-tracing in the source plane)

Parameters:
  • kwargs_ps – point source keyword argument list
  • kwargs_lens – lens model keyword argument list
  • tolerance – Eucledian distance between the source positions ray-traced backwards to be tolerated
Returns:

bool: True, if requirement on tolerance is fulfilled, False if not.

classmethod check_positive_flux(kwargs_ps)[source]

check whether inferred linear parameters are positive

Parameters:kwargs_ps – point source keyword argument list
Returns:bool, True, if all ‘point_amp’ parameters are positive semi-definite
delete_lens_model_cache()[source]

deletes the variables saved for a specific lens model

Returns:None
image_amplitude(kwargs_ps, kwargs_lens, k=None)[source]

returns the image amplitudes

Parameters:
  • kwargs_ps – point source keyword argument list
  • kwargs_lens – lens model keyword argument list
  • k – None, int or list of int’s to select a subset of the point source models in the return
Returns:

list of image amplitudes per model component

image_position(kwargs_ps, kwargs_lens, k=None, original_position=False)[source]

image positions as observed on the sky of the point sources

Parameters:
  • kwargs_ps – point source parameter keyword argument list
  • kwargs_lens – lens model keyword argument list
  • k – None, int or boolean list; only returns a subset of the model predictions
  • original_position – boolean (only applies to ‘LENSED_POSITION’ models), returns the image positions in the model parameters and does not re-compute images (which might be differently ordered) in case of the lens equation solver
Returns:

list of: list of image positions per point source model component

linear_response_set(kwargs_ps, kwargs_lens=None, with_amp=False)[source]
Parameters:
  • kwargs_ps – point source keyword argument list
  • kwargs_lens – lens model keyword argument list
  • with_amp – bool, if True returns the image amplitude derived from kwargs_ps, otherwise the magnification of the lens model
Returns:

ra_pos, dec_pos, amp, n

num_basis(kwargs_ps, kwargs_lens)[source]

number of basis functions for linear inversion

Parameters:
  • kwargs_ps – point source keyword argument list
  • kwargs_lens – lens model keyword argument list
Returns:

int

point_source_list(kwargs_ps, kwargs_lens, k=None, with_amp=True)[source]

returns the coordinates and amplitudes of all point sources in a single array

Parameters:
  • kwargs_ps – point source keyword argument list
  • kwargs_lens – lens model keyword argument list
  • k – None, int or list of int’s to select a subset of the point source models in the return
  • with_amp – bool, if False, ignores the amplitude parameters in the return and instead provides ones for each point source image
Returns:

ra_array, dec_array, amp_array

set_amplitudes(amp_list, kwargs_ps)[source]

translates the amplitude parameters into the convention of the keyword argument list currently only used in SimAPI to transform magnitudes to amplitudes in the lenstronomy conventions

Parameters:
  • amp_list – list of model amplitudes for each point source model
  • kwargs_ps – list of point source keywords
Returns:

overwrites kwargs_ps with new amplitudes

set_save_cache(bool)[source]

set the save cache boolean to new value

Parameters:bool – bool, if True, saves (or uses a previously saved) values
Returns:updated class and sub-class instances to either save or not save the point source information in cache
source_amplitude(kwargs_ps, kwargs_lens)[source]

intrinsic (unlensed) point source amplitudes

Parameters:
  • kwargs_ps – point source keyword argument list
  • kwargs_lens – lens model keyword argument list
Returns:

list of intrinsic (unlensed) point source amplitudes

source_position(kwargs_ps, kwargs_lens)[source]

intrinsic source positions of the point sources

Parameters:
  • kwargs_ps – keyword argument list of point source models
  • kwargs_lens – keyword argument list of lens models
Returns:

list of source positions for each point source model

update_lens_model(lens_model_class)[source]
Parameters:lens_model_class – instance of LensModel class
Returns:update instance of lens model class
update_linear(param, i, kwargs_ps, kwargs_lens)[source]
Parameters:
  • param – list of floats corresponding ot the parameters being sampled
  • i – index of the first parameter relevant for this class
  • kwargs_ps – point source keyword argument list
  • kwargs_lens – lens model keyword argument list
Returns:

kwargs_ps with updated linear parameters, index of the next parameter relevant for another class

update_search_window(search_window, x_center, y_center, min_distance=None, only_from_unspecified=False)[source]

update the search area for the lens equation solver

Parameters:
  • search_window – search_window: window size of the image position search with the lens equation solver.
  • x_center – center of search window
  • y_center – center of search window
  • min_distance – minimum search distance
  • only_from_unspecified – bool, if True, only sets keywords that previously have not been set
Returns:

updated self instances

lenstronomy.PointSource.point_source_cached module

class lenstronomy.PointSource.point_source_cached.PointSourceCached(point_source_model, save_cache=False)[source]

Bases: object

This class is the same as PointSource() except that it saves image and source positions in cache. This speeds-up repeated calls for the same source and lens model and avoids duplicating the lens equation solving. Attention: cache needs to be deleted before calling functions with different lens and point source parameters.

delete_lens_model_cache()[source]
image_amplitude(kwargs_ps, kwargs_lens=None, magnification_limit=None, kwargs_lens_eqn_solver=None)[source]

image brightness amplitudes

Parameters:
  • kwargs_ps – keyword arguments of the point source model
  • kwargs_lens – keyword argument list of the lens model(s), only used when requiring the lens equation solver
  • magnification_limit – float >0 or None, if float is set and additional images are computed, only those images will be computed that exceed the lensing magnification (absolute value) limit
  • kwargs_lens_eqn_solver – keyword arguments specifying the numerical settings for the lens equation solver see LensEquationSolver() class for details
Returns:

array of image amplitudes

image_position(kwargs_ps, kwargs_lens=None, magnification_limit=None, kwargs_lens_eqn_solver=None)[source]

on-sky image positions

Parameters:
  • kwargs_ps – keyword arguments of the point source model
  • kwargs_lens – keyword argument list of the lens model(s), only used when requiring the lens equation solver
  • magnification_limit – float >0 or None, if float is set and additional images are computed, only those images will be computed that exceed the lensing magnification (absolute value) limit
  • kwargs_lens_eqn_solver – keyword arguments specifying the numerical settings for the lens equation solver see LensEquationSolver() class for details
Returns:

image positions in x, y as arrays

set_save_cache(bool)[source]
source_amplitude(kwargs_ps, kwargs_lens=None)[source]

intrinsic brightness amplitude of point source

Parameters:
  • kwargs_ps – keyword arguments of the point source model
  • kwargs_lens – keyword argument list of the lens model(s), only used when positions are defined in image plane and have to be ray-traced back
Returns:

brightness amplitude (as numpy array)

source_position(kwargs_ps, kwargs_lens=None)[source]

original source position (prior to lensing)

Parameters:
  • kwargs_ps – point source keyword arguments
  • kwargs_lens – lens model keyword argument list (only used when required)
Returns:

x, y position

update_lens_model(lens_model_class)[source]

lenstronomy.PointSource.point_source_param module

class lenstronomy.PointSource.point_source_param.PointSourceParam(model_list, kwargs_fixed, num_point_source_list=None, linear_solver=True, fixed_magnification_list=None, kwargs_lower=None, kwargs_upper=None)[source]

Bases: object

add_fix_linear(kwargs_fixed)[source]

updates fixed keyword argument list with linear parameters

Parameters:kwargs_fixed – list of keyword arguments held fixed during sampling
Returns:updated keyword argument list
getParams(args, i)[source]
Parameters:
  • args – sorted list of floats corresponding to the parameters being sampled
  • i – int, index of first entry relevant for being managed by this class
Returns:

keyword argument list of point sources, index relevant for the next class

num_param()[source]

number of parameters and their names

Returns:int, list of parameter names
num_param_linear()[source]
Returns:number of linear parameters
setParams(kwargs_list)[source]
Parameters:kwargs_list – keyword argument list
Returns:sorted list of parameters being sampled extracted from kwargs_list

Module contents