autofit.SamplesStored#

class autofit.SamplesStored(model: AbstractPriorModel, sample_list: List[Sample], samples_info: Optional[Dict] = None)[source]#

Bases: SamplesPDF

The Samples of a non-linear search, specifically the samples of a NonLinearSearch which maps out the posterior of parameter space and thus does provide information on parameter errors.

Parameters:

model (af.ModelMapper) – Maps input vectors of unit parameter values to physical values and model instances via priors.

Methods

draw_randomly_via_pdf

The parameter vector of an individual sample of the non-linear search drawn randomly from the PDF, returned as a 1D list.

error_magnitudes_at_sigma

The magnitude of every error after marginalization in 1D at an input sigma value of the probability density function (PDF), returned as two lists of values corresponding to the lower and upper errors.

errors_at_lower_sigma

The lower error of every parameter marginalized in 1D at an input sigma value of its probability density function (PDF), returned as a list.

errors_at_sigma

The lower and upper error of every parameter marginalized in 1D at an input sigma value of its probability density function (PDF), returned as a list.

errors_at_upper_sigma

The upper error of every parameter marginalized in 1D at an input sigma value of its probability density function (PDF), returned as a list.

from_list_info_and_model

from_sample_index

The parameters of an individual sample of the non-linear search, returned as a model instance.

from_table

Write a table of parameters, posteriors, priors and likelihoods

info_to_json

max_log_likelihood

The parameters of the maximum log likelihood sample of the NonLinearSearch returned as a model instance or list of values.

max_log_posterior

The parameters of the maximum log posterior sample of the NonLinearSearch returned as a model instance.

median_pdf

The median of the probability density function (PDF) of every parameter marginalized in 1D, returned as a model instance or list of values.

minimise

A copy of this object with only important samples retained

model_absolute

Returns a model where every free parameter is a GaussianPrior with mean the previous result's inferred maximum log likelihood parameter values and sigma the input absolute value a.

model_bounded

Returns a model where every free parameter is a UniformPrior with lower_limit and upper_limit the previous result's inferred maximum log likelihood parameter values minus and plus the bound `b.

model_relative

Returns a model where every free parameter is a GaussianPrior with mean the previous result's inferred maximum log likelihood parameter values and sigma a relative value from the result r.

offset_values_via_input_values

The values of an input_vector offset by the median_pdf(as_instance=False) (the PDF medians).

path_map_for_model

samples_above_weight_threshold_from

Returns a new Samples object containing only the samples with a weight above the input threshold.

save_covariance_matrix

Save the covariance matrix as a CSV file.

subsamples

summary

values_at_lower_sigma

The lower value of every parameter marginalized in 1D at an input sigma value of its probability density function (PDF), returned as a list.

values_at_sigma

The value of every parameter marginalized in 1D at an input sigma value of its probability density function (PDF), returned as two lists of values corresponding to the lower and upper values parameter values.

values_at_upper_sigma

The upper value of every parameter marginalized in 1D at an input sigma value of its probability density function (PDF), returned as a list.

values_for_path

Returns the value for a variable with a given path for each sample in the model

with_paths

Create a copy of this object with only attributes specified by a list of paths.

without_paths

Create a copy of this object with only attributes not specified by a list of paths.

write_table

Write a table of parameters, posteriors, priors and likelihoods.

Attributes

covariance_matrix

Compute the covariance matrix of the non-linear search samples, using the method np.cov() which is described at the following link:

instance

instances

One model instance for each sample

log_evidence

log_likelihood

log_likelihood_list

log_posterior_list

log_prior_list

max_log_likelihood_index

The index of the sample with the highest log likelihood.

max_log_likelihood_sample

The index of the sample with the highest log likelihood.

max_log_posterior_index

The index of the sample with the highest log posterior.

max_log_posterior_sample

names

A list of names of unique priors in the same order as prior ids (and therefore sample columns)

parameter_lists

parameters_extract

paths

A list of paths to unique priors in the same order as prior ids (and therefore sample columns)

pdf_converged

To analyse and visualize samples the analysis must be sufficiently converged to produce smooth enough PDF for error estimate and PDF generation.

prior_means

The mean of every parameter used to link its inferred values and errors to priors used to sample the same (or similar) parameters in a subsequent search, where:

time

total_iterations

total_samples

unconverged_sample_size

If a set of samples are unconverged, alternative methods to compute their means, errors, etc are used.

weight_list