Source code for autolens.imaging.model.analysis

import logging
import numpy as np
from typing import Dict, Optional, Tuple

from autoconf.dictable import to_dict

import autofit as af
import autogalaxy as ag

from autoarray.exc import PixelizationException

from autolens.analysis.analysis.dataset import AnalysisDataset
from autolens.analysis.preloads import Preloads
from autolens.imaging.model.result import ResultImaging
from autolens.imaging.model.visualizer import VisualizerImaging
from autolens.imaging.fit_imaging import FitImaging

from autolens import exc

logger = logging.getLogger(__name__)

logger.setLevel(level="INFO")


[docs] class AnalysisImaging(AnalysisDataset): Result = ResultImaging Visualizer = VisualizerImaging
[docs] def modify_before_fit(self, paths: af.DirectoryPaths, model: af.Collection): """ This function is called immediately before the non-linear search begins and performs final tasks and checks before it begins. This function: - Checks that the adapt-dataset is consistent with previous adapt-datasets if the model-fit is being resumed from a previous run. - Checks the model and raises exceptions if certain critieria are not met. Once inherited from it also visualizes objects which do not change throughout the model fit like the dataset. Parameters ---------- paths The paths object which manages all paths, e.g. where the non-linear search outputs are stored, visualization and the pickled objects used by the aggregator output by this function. model The model object, which includes model components representing the galaxies that are fitted to the imaging data. """ super().modify_before_fit(paths=paths, model=model) if not paths.is_complete: self.set_preloads(paths=paths, model=model) return self
[docs] def log_likelihood_function(self, instance: af.ModelInstance) -> float: """ Given an instance of the model, where the model parameters are set via a non-linear search, fit the model instance to the imaging dataset. This function returns a log likelihood which is used by the non-linear search to guide the model-fit. For this analysis class, this function performs the following steps: 1) If the analysis has a adapt image, associated the model galaxy images of this dataset to the galaxies in the model instance. 2) Extract attributes which model aspects of the data reductions, like the scaling the background sky and background noise. 3) Extracts all galaxies from the model instance and set up a `Tracer`, which includes ordering the galaxies by redshift to set up each `Plane`. 4) Use the `Tracer` and other attributes to create a `FitImaging` object, which performs steps such as creating model images of every galaxy in the tracer, blurring them with the imaging dataset's PSF and computing residuals, a chi-squared statistic and the log likelihood. Certain models will fail to fit the dataset and raise an exception. For example if an `Inversion` is used, the linear algebra calculation may be invalid and raise an Exception. In such circumstances the model is discarded and its likelihood value is passed to the non-linear search in a way that it ignores it (for example, using a value of -1.0e99). Parameters ---------- instance An instance of the model that is being fitted to the data by this analysis (whose parameters have been set via a non-linear search). Returns ------- float The log likelihood indicating how well this model instance fitted the imaging data. """ try: log_likelihood_positions_overwrite = self.log_likelihood_positions_overwrite_from( instance=instance ) if log_likelihood_positions_overwrite is not None: return log_likelihood_positions_overwrite except Exception as e: raise e if log_likelihood_positions_overwrite is not None: return log_likelihood_positions_overwrite try: return self.fit_from(instance=instance).figure_of_merit except ( PixelizationException, exc.PixelizationException, exc.InversionException, exc.GridException, exc.MeshException, ValueError, TypeError, np.linalg.LinAlgError, OverflowError, ) as e: raise exc.FitException from e
[docs] def fit_from( self, instance: af.ModelInstance, preload_overwrite: Optional[Preloads] = None, run_time_dict: Optional[Dict] = None, ) -> FitImaging: """ Given a model instance create a `FitImaging` object. This function is used in the `log_likelihood_function` to fit the model to the imaging data and compute the log likelihood. Parameters ---------- instance An instance of the model that is being fitted to the data by this analysis (whose parameters have been set via a non-linear search). preload_overwrite If a `Preload` object is input this is used instead of the preloads stored as an attribute in the analysis. check_positions Whether the multiple image positions of the lensed source should be checked, i.e. whether they trace within the position threshold of one another in the source plane. run_time_dict A dictionary which times functions called to fit the model to data, for profiling. Returns ------- FitImaging The fit of the plane to the imaging dataset, which includes the log likelihood. """ tracer = self.tracer_via_instance_from( instance=instance, run_time_dict=run_time_dict ) dataset_model = self.dataset_model_via_instance_from(instance=instance) adapt_images = self.adapt_images_via_instance_from(instance=instance) preloads = preload_overwrite or self.preloads return FitImaging( dataset=self.dataset, tracer=tracer, dataset_model=dataset_model, adapt_images=adapt_images, settings_inversion=self.settings_inversion, preloads=preloads, run_time_dict=run_time_dict, )
[docs] def save_attributes(self, paths: af.DirectoryPaths): """ Before the non-linear search begins, this routine saves attributes of the `Analysis` object to the `files` folder such that they can be loaded after the analysis using PyAutoFit's database and aggregator tools. For this analysis, it uses the `AnalysisDataset` object's method to output the following: - The dataset's data. - The dataset's noise-map. - The settings associated with the dataset. - The settings associated with the inversion. - The settings associated with the pixelization. - The Cosmology. - The adapt image's model image and galaxy images, if used. This function also outputs attributes specific to an imaging dataset: - Its PSF. - Its mask. - The positions of the brightest pixels in the lensed source which are used to discard mass models. - The preloaded image-plane source plane pixelization if used by the analysis. This ensures that differences in the scikit-learn library do not lead to different pixelizations being computed if results are transferred from a HPC to laptop. It is common for these attributes to be loaded by many of the template aggregator functions given in the `aggregator` modules. For example, when using the database tools to perform a fit, the default behaviour is for the dataset, settings and other attributes necessary to perform the fit to be loaded via the pickle files output by this function. Parameters ---------- paths The paths object which manages all paths, e.g. where the non-linear search outputs are stored, visualization, and the pickled objects used by the aggregator output by this function. """ super().save_attributes(paths=paths) analysis = ag.AnalysisImaging( dataset=self.dataset, ) analysis.save_attributes(paths=paths) if self.positions_likelihood is not None: paths.save_json( name="positions", object_dict=to_dict(self.positions_likelihood.positions), prefix="dataset", )
[docs] def profile_log_likelihood_function( self, instance: af.ModelInstance, paths: Optional[af.DirectoryPaths] = None ) -> Tuple[Dict, Dict]: """ This function is optionally called throughout a model-fit to profile the log likelihood function. All function calls inside the `log_likelihood_function` that are decorated with the `profile_func` are timed with their times stored in a dictionary called the `run_time_dict`. An `info_dict` is also created which stores information on aspects of the model and dataset that dictate run times, so the profiled times can be interpreted with this context. The results of this profiling are then output to hard-disk in the `preloads` folder of the model-fit results, which they can be inspected to ensure run-times are as expected. Parameters ---------- instance An instance of the model that is being fitted to the data by this analysis (whose parameters have been set via a non-linear search). paths The paths object which manages all paths, e.g. where the non-linear search outputs are stored, visualization and the pickled objects used by the aggregator output by this function. Returns ------- Two dictionaries, the profiling dictionary and info dictionary, which contain the profiling times of the `log_likelihood_function` and information on the model and dataset used to perform the profiling. """ run_time_dict, info_dict = super().profile_log_likelihood_function( instance=instance, ) info_dict["psf_shape_2d"] = self.dataset.psf.shape_native self.output_profiling_info(paths=paths, run_time_dict=run_time_dict, info_dict=info_dict) return run_time_dict, info_dict