Source code for gammapy.modeling.models.core

# Licensed under a 3-clause BSD style license - see LICENSE.rst
import collections.abc
import copy
import logging
from os.path import split
import numpy as np
import astropy.units as u
from astropy.coordinates import SkyCoord
from astropy.table import Table
import matplotlib.pyplot as plt
import yaml
from gammapy.maps import Map, RegionGeom
from gammapy.modeling import Covariance, Parameter, Parameters
from gammapy.modeling.covariance import copy_covariance
from gammapy.utils.scripts import make_name, make_path

__all__ = ["Model", "Models", "DatasetModels", "ModelBase"]


log = logging.getLogger(__name__)


def _set_link(shared_register, model):
    for param in model.parameters:
        name = param.name
        link_label = param._link_label_io
        if link_label is not None:
            if link_label in shared_register:
                new_param = shared_register[link_label]
                setattr(model, name, new_param)
            else:
                shared_register[link_label] = param
    return shared_register


def _get_model_class_from_dict(data):
    """get a model class from a dict"""
    from . import (
        MODEL_REGISTRY,
        SPATIAL_MODEL_REGISTRY,
        SPECTRAL_MODEL_REGISTRY,
        TEMPORAL_MODEL_REGISTRY,
    )

    if "type" in data:
        cls = MODEL_REGISTRY.get_cls(data["type"])
    elif "spatial" in data:
        cls = SPATIAL_MODEL_REGISTRY.get_cls(data["spatial"]["type"])
    elif "spectral" in data:
        cls = SPECTRAL_MODEL_REGISTRY.get_cls(data["spectral"]["type"])
    elif "temporal" in data:
        cls = TEMPORAL_MODEL_REGISTRY.get_cls(data["temporal"]["type"])
    return cls


def _build_parameters_from_dict(data, default_parameters):
    """Build Parameters object from input dict and default  parameter values."""
    par_data = []

    input_names = [_["name"] for _ in data]

    for par in default_parameters:
        par_dict = par.to_dict()
        try:
            index = input_names.index(par_dict["name"])
            par_dict.update(data[index])
        except ValueError:
            log.warning(
                f"Parameter '{par_dict['name']}' not defined in YAML file."
                f" Using default value: {par_dict['value']} {par_dict['unit']}"
            )
        par_data.append(par_dict)

    return Parameters.from_dict(par_data)


[docs]class ModelBase: """Model base class.""" _type = None def __init__(self, **kwargs): # Copy default parameters from the class to the instance default_parameters = self.default_parameters.copy() for par in default_parameters: value = kwargs.get(par.name, par) if not isinstance(value, Parameter): par.quantity = u.Quantity(value) else: par = value setattr(self, par.name, par) self._covariance = Covariance(self.parameters) def __getattribute__(self, name): value = object.__getattribute__(self, name) if isinstance(value, Parameter): return value.__get__(self, None) return value @property def type(self): return self._type def __init_subclass__(cls, **kwargs): # Add parameters list on the model sub-class (not instances) cls.default_parameters = Parameters( [_ for _ in cls.__dict__.values() if isinstance(_, Parameter)] )
[docs] @classmethod def from_parameters(cls, parameters, **kwargs): """Create model from parameter list Parameters ---------- parameters : `Parameters` Parameters for init Returns ------- model : `Model` Model instance """ for par in parameters: kwargs[par.name] = par return cls(**kwargs)
def _check_covariance(self): if not self.parameters == self._covariance.parameters: self._covariance = Covariance(self.parameters) @property def covariance(self): self._check_covariance() for par in self.parameters: pars = Parameters([par]) error = np.nan_to_num(par.error**2, nan=1) covar = Covariance(pars, data=[[error]]) self._covariance.set_subcovariance(covar) return self._covariance @covariance.setter def covariance(self, covariance): self._check_covariance() self._covariance.data = covariance for par in self.parameters: pars = Parameters([par]) variance = self._covariance.get_subcovariance(pars) par.error = np.sqrt(variance) @property def parameters(self): """Parameters (`~gammapy.modeling.Parameters`)""" return Parameters( [getattr(self, name) for name in self.default_parameters.names] ) @copy_covariance def copy(self, **kwargs): """A deep copy.""" return copy.deepcopy(self)
[docs] def to_dict(self, full_output=False): """Create dict for YAML serialisation""" tag = self.tag[0] if isinstance(self.tag, list) else self.tag params = self.parameters.to_dict() if not full_output: for par, par_default in zip(params, self.default_parameters): init = par_default.to_dict() for item in [ "min", "max", "error", "interp", "scale_method", "is_norm", ]: default = init[item] if par[item] == default or ( np.isnan(par[item]) and np.isnan(default) ): del par[item] if par["frozen"] == init["frozen"]: del par["frozen"] if init["unit"] == "": del par["unit"] data = {"type": tag, "parameters": params} if self.type is None: return data else: return {self.type: data}
[docs] @classmethod def from_dict(cls, data): kwargs = {} key0 = next(iter(data)) if key0 in ["spatial", "temporal", "spectral"]: data = data[key0] if data["type"] not in cls.tag: raise ValueError( f"Invalid model type {data['type']} for class {cls.__name__}" ) parameters = _build_parameters_from_dict( data["parameters"], cls.default_parameters ) # TODO: this is a special case for spatial models, maybe better move to # `SpatialModel` base class if "frame" in data: kwargs["frame"] = data["frame"] return cls.from_parameters(parameters, **kwargs)
def __str__(self): string = f"{self.__class__.__name__}\n" if len(self.parameters) > 0: string += f"\n{self.parameters.to_table()}" return string @property def frozen(self): """Frozen status of a model, True if all parameters are frozen""" return np.all([p.frozen for p in self.parameters])
[docs] def freeze(self): """Freeze all parameters""" self.parameters.freeze_all()
[docs] def unfreeze(self): """Restore parameters frozen status to default""" for p, default in zip(self.parameters, self.default_parameters): p.frozen = default.frozen
[docs] def reassign(self, datasets_names, new_datasets_names): """Reassign a model from one dataset to another Parameters ---------- datasets_names : str or list Name of the datasets where the model is currently defined new_datasets_names : str or list Name of the datasets where the model should be defined instead. If multiple names are given the two list must have the save length, as the reassignment is element-wise. Returns ------- model : `Model` Reassigned model. """ model = self.copy(name=self.name) if not isinstance(datasets_names, list): datasets_names = [datasets_names] if not isinstance(new_datasets_names, list): new_datasets_names = [new_datasets_names] if isinstance(model.datasets_names, str): model.datasets_names = [model.datasets_names] if getattr(model, "datasets_names", None): for name, name_new in zip(datasets_names, new_datasets_names): model.datasets_names = [ _.replace(name, name_new) for _ in model.datasets_names ] return model
[docs]class Model: """Model class that contains only methods to create a model listed in the registries."""
[docs] @staticmethod def create(tag, model_type=None, *args, **kwargs): """Create a model instance. Examples -------- >>> from gammapy.modeling.models import Model >>> spectral_model = Model.create( "pl-2", model_type="spectral", amplitude="1e-10 cm-2 s-1", index=3 ) >>> type(spectral_model) <class 'gammapy.modeling.models.spectral.PowerLaw2SpectralModel'> """ data = {"type": tag} if model_type is not None: data = {model_type: data} cls = _get_model_class_from_dict(data) return cls(*args, **kwargs)
[docs] @staticmethod def from_dict(data): """Create a model instance from a dict""" cls = _get_model_class_from_dict(data) return cls.from_dict(data)
[docs]class DatasetModels(collections.abc.Sequence): """Immutable models container Parameters ---------- models : `SkyModel`, list of `SkyModel` or `Models` Sky models """ def __init__(self, models=None): if models is None: models = [] if isinstance(models, (Models, DatasetModels)): models = models._models elif isinstance(models, ModelBase): models = [models] elif not isinstance(models, list): raise TypeError(f"Invalid type: {models!r}") unique_names = [] for model in models: if model.name in unique_names: raise (ValueError("Model names must be unique")) unique_names.append(model.name) self._models = models self._covar_file = None self._covariance = Covariance(self.parameters) def _check_covariance(self): if not self.parameters == self._covariance.parameters: self._covariance = Covariance.from_stack( [model.covariance for model in self._models] ) @property def covariance(self): self._check_covariance() for model in self._models: self._covariance.set_subcovariance(model.covariance) return self._covariance @covariance.setter def covariance(self, covariance): self._check_covariance() self._covariance.data = covariance for model in self._models: subcovar = self._covariance.get_subcovariance(model.covariance.parameters) model.covariance = subcovar @property def parameters(self): return Parameters.from_stack([_.parameters for _ in self._models]) @property def parameters_unique_names(self): """List of unique parameter names as model_name.par_type.par_name""" names = [] for model in self: for par in model.parameters: components = [model.name, par.type, par.name] name = ".".join(components) names.append(name) return names @property def names(self): return [m.name for m in self._models]
[docs] @classmethod def read(cls, filename): """Read from YAML file.""" yaml_str = make_path(filename).read_text() path, filename = split(filename) return cls.from_yaml(yaml_str, path=path)
[docs] @classmethod def from_yaml(cls, yaml_str, path=""): """Create from YAML string.""" data = yaml.safe_load(yaml_str) return cls.from_dict(data, path=path)
[docs] @classmethod def from_dict(cls, data, path=""): """Create from dict.""" from . import MODEL_REGISTRY, SkyModel models = [] for component in data["components"]: model_cls = MODEL_REGISTRY.get_cls(component["type"]) model = model_cls.from_dict(component) models.append(model) models = cls(models) if "covariance" in data: filename = data["covariance"] path = make_path(path) if not (path / filename).exists(): path, filename = split(filename) models.read_covariance(path, filename, format="ascii.fixed_width") shared_register = {} for model in models: if isinstance(model, SkyModel): submodels = [ model.spectral_model, model.spatial_model, model.temporal_model, ] for submodel in submodels: if submodel is not None: shared_register = _set_link(shared_register, submodel) else: shared_register = _set_link(shared_register, model) return models
[docs] def write( self, path, overwrite=False, full_output=False, overwrite_templates=False, write_covariance=True, ): """Write to YAML file. Parameters ---------- path : `pathlib.Path` or str path to write files overwrite : bool overwrite YAML files full_output : bool Store full parameter output. overwrite_templates : bool overwrite templates FITS files write_covariance : bool save covariance or not """ base_path, _ = split(path) path = make_path(path) base_path = make_path(base_path) if path.exists() and not overwrite: raise IOError(f"File exists already: {path}") if ( write_covariance and self.covariance is not None and len(self.parameters) != 0 ): filecovar = path.stem + "_covariance.dat" kwargs = dict( format="ascii.fixed_width", delimiter="|", overwrite=overwrite ) self.write_covariance(base_path / filecovar, **kwargs) self._covar_file = filecovar path.write_text(self.to_yaml(full_output, overwrite_templates))
[docs] def to_yaml(self, full_output=False, overwrite_templates=False): """Convert to YAML string.""" data = self.to_dict(full_output, overwrite_templates) return yaml.dump( data, sort_keys=False, indent=4, width=80, default_flow_style=False )
[docs] def to_dict(self, full_output=False, overwrite_templates=False): """Convert to dict.""" self.update_link_label() models_data = [] for model in self._models: model_data = model.to_dict(full_output) models_data.append(model_data) if ( hasattr(model, "spatial_model") and model.spatial_model is not None and "template" in model.spatial_model.tag ): model.spatial_model.write(overwrite=overwrite_templates) if self._covar_file is not None: return { "components": models_data, "covariance": str(self._covar_file), } else: return {"components": models_data}
[docs] def to_parameters_table(self): """Convert Models parameters to an astropy Table.""" table = self.parameters.to_table() # Warning: splitting of parameters will break is source name has a "." in its name. model_name = [name.split(".")[0] for name in self.parameters_unique_names] table.add_column(model_name, name="model", index=0) return table
[docs] def update_parameters_from_table(self, t): """Update Models from an astropy Table.""" parameters_dict = [dict(zip(t.colnames, row)) for row in t] for k, data in enumerate(parameters_dict): self.parameters[k].update_from_dict(data)
[docs] def read_covariance(self, path, filename="_covariance.dat", **kwargs): """Read covariance data from file Parameters ---------- path : str or `Path` Base path filename : str Filename **kwargs : dict Keyword arguments passed to `~astropy.table.Table.read` """ path = make_path(path) filepath = str(path / filename) t = Table.read(filepath, **kwargs) t.remove_column("Parameters") arr = np.array(t) data = arr.view(float).reshape(arr.shape + (-1,)) self.covariance = data self._covar_file = filename
[docs] def write_covariance(self, filename, **kwargs): """Write covariance to file Parameters ---------- filename : str Filename **kwargs : dict Keyword arguments passed to `~astropy.table.Table.write` """ names = self.parameters_unique_names table = Table() table["Parameters"] = names for idx, name in enumerate(names): values = self.covariance.data[idx] table[str(idx)] = values table.write(make_path(filename), **kwargs)
def __str__(self): self.update_link_label() str_ = f"{self.__class__.__name__}\n\n" for idx, model in enumerate(self): str_ += f"Component {idx}: " str_ += str(model) return str_.expandtabs(tabsize=2) def __add__(self, other): if isinstance(other, (Models, list)): return Models([*self, *other]) elif isinstance(other, ModelBase): if other.name in self.names: raise (ValueError("Model names must be unique")) return Models([*self, other]) else: raise TypeError(f"Invalid type: {other!r}") def __getitem__(self, key): if isinstance(key, np.ndarray) and key.dtype == bool: return self.__class__(list(np.array(self._models)[key])) else: return self._models[self.index(key)]
[docs] def index(self, key): if isinstance(key, (int, slice)): return key elif isinstance(key, str): return self.names.index(key) elif isinstance(key, ModelBase): return self._models.index(key) else: raise TypeError(f"Invalid type: {type(key)!r}")
def __len__(self): return len(self._models) def _ipython_key_completions_(self): return self.names @copy_covariance def copy(self, copy_data=False): """A deep copy. Parameters ---------- copy_data : bool Whether to copy data attached to template models Returns ------- models: `Models` Copied models. """ models = [] for model in self: model_copy = model.copy(name=model.name, copy_data=copy_data) models.append(model_copy) return self.__class__(models=models)
[docs] def select( self, name_substring=None, datasets_names=None, tag=None, model_type=None, frozen=None, ): """Select models that meet all specified conditions Parameters ---------- name_substring : str Substring contained in the model name datasets_names : str or list Name of the dataset tag : str or list Model tag model_type : {None, spatial, spectral} Type of model, used together with "tag", if the tag is not unique. frozen : bool Select models with all parameters frozen if True, exclude them if False. Returns ------- models : `DatasetModels` Selected models """ mask = self.selection_mask( name_substring, datasets_names, tag, model_type, frozen ) return self[mask]
[docs] def selection_mask( self, name_substring=None, datasets_names=None, tag=None, model_type=None, frozen=None, ): """Create a mask of models, that meet all specified conditions Parameters ---------- name_substring : str Substring contained in the model name datasets_names : str or list of str Name of the dataset tag : str or list of str Model tag model_type : {None, spatial, spectral} Type of model, used together with "tag", if the tag is not unique. frozen : bool Select models with all parameters frozen if True, exclude them if False. Returns ------- mask : `numpy.array` Boolean mask, True for selected models """ selection = np.ones(len(self), dtype=bool) if tag and not isinstance(tag, list): tag = [tag] if datasets_names and not isinstance(datasets_names, list): datasets_names = [datasets_names] for idx, model in enumerate(self): if name_substring: selection[idx] &= name_substring in model.name if datasets_names: selection[idx] &= model.datasets_names is None or np.any( [name in model.datasets_names for name in datasets_names] ) if tag: if model_type is None: sub_model = model else: sub_model = getattr(model, f"{model_type}_model", None) if sub_model: selection[idx] &= np.any([t in sub_model.tag for t in tag]) else: selection[idx] &= False if frozen is not None: if frozen: selection[idx] &= model.frozen else: selection[idx] &= ~model.frozen return np.array(selection, dtype=bool)
[docs] def select_mask(self, mask, margin="0 deg", use_evaluation_region=True): """Check if sky models contribute within a mask map. Parameters ---------- mask : `~gammapy.maps.WcsNDMap` of boolean type Map containing a boolean mask margin : `~astropy.unit.Quantity` Add a margin in degree to the source evaluation radius. Used to take into account PSF width. use_evaluation_region : bool Account for the extension of the model or not. The default is True. Returns ------- models : `DatasetModels` Selected models contributing inside the region where mask==True """ models = [] if not mask.geom.is_image: mask = mask.reduce_over_axes(func=np.logical_or) for model in self.select(tag="sky-model"): if use_evaluation_region: contributes = model.contributes(mask=mask, margin=margin) else: contributes = mask.get_by_coord(model.position, fill_value=0) if np.any(contributes): models.append(model) return self.__class__(models=models)
[docs] def select_region(self, regions, wcs=None): """Select sky models with center position contained within a given region Parameters ---------- regions : str, `~regions.Region` or list of `~regions.Region` Region or list of regions (pixel or sky regions accepted). A region can be defined as a string ind DS9 format as well. See http://ds9.si.edu/doc/ref/region.html for details. wcs : `~astropy.wcs.WCS` World coordinate system transformation Returns ------- models : `DatasetModels` Selected models """ geom = RegionGeom.from_regions(regions, wcs=wcs) models = [] for model in self.select(tag="sky-model"): if geom.contains(model.position): models.append(model) return self.__class__(models=models)
[docs] def restore_status(self, restore_values=True): """Context manager to restore status. A copy of the values is made on enter, and those values are restored on exit. Parameters ---------- restore_values : bool Restore values if True, otherwise restore only frozen status and covariance matrix. """ return restore_models_status(self, restore_values)
[docs] def set_parameters_bounds( self, tag, model_type, parameters_names=None, min=None, max=None, value=None ): """Set bounds for the selected models types and parameters names Parameters ---------- tag : str or list Tag of the models model_type : {"spatial", "spectral", "temporal"} Type of model parameters_names : str or list parameters names min : float min value max : float max value value : float init value """ models = self.select(tag=tag, model_type=model_type) parameters = models.parameters.select(name=parameters_names, type=model_type) n = len(parameters) if min is not None: parameters.min = np.ones(n) * min if max is not None: parameters.max = np.ones(n) * max if value is not None: parameters.value = np.ones(n) * value
[docs] def freeze(self, model_type=None): """Freeze parameters depending on model type Parameters ---------- model_type : {None, "spatial", "spectral"} freeze all parameters or only spatial or only spectral """ for m in self: m.freeze(model_type)
[docs] def unfreeze(self, model_type=None): """Restore parameters frozen status to default depending on model type Parameters ---------- model_type : {None, "spatial", "spectral"} restore frozen status to default for all parameters or only spatial or only spectral """ for m in self: m.unfreeze(model_type)
@property def frozen(self): """Boolean mask, True if all parameters of a given model are frozen""" return np.all([m.frozen for m in self])
[docs] def reassign(self, dataset_name, new_dataset_name): """Reassign a model from one dataset to another Parameters ---------- dataset_name : str or list Name of the datasets where the model is currently defined new_dataset_name : str or list Name of the datasets where the model should be defined instead. If multiple names are given the two list must have the save length, as the reassignment is element-wise. """ models = [m.reassign(dataset_name, new_dataset_name) for m in self] return self.__class__(models)
[docs] def to_template_sky_model(self, geom, spectral_model=None, name=None): """Merge a list of models into a single `~gammapy.modeling.models.SkyModel` Parameters ---------- geom : `Geom` Map geometry of the result template model. spectral_model : `~gammapy.modeling.models.SpectralModel` One of the NormSpectralMdel name : str Name of the new model Returns ------- model : `SkyModel` Template sky model. """ from . import PowerLawNormSpectralModel, SkyModel, TemplateSpatialModel unit = u.Unit("1 / (cm2 s sr TeV)") map_ = Map.from_geom(geom, unit=unit) for m in self: map_ += m.evaluate_geom(geom).to(unit) spatial_model = TemplateSpatialModel(map_, normalize=False) if spectral_model is None: spectral_model = PowerLawNormSpectralModel() return SkyModel( spectral_model=spectral_model, spatial_model=spatial_model, name=name )
@property def positions(self): """Positions of the models (`~astropy.coordinates.SkyCoord`)""" positions = [] for model in self.select(tag="sky-model"): if model.position: positions.append(model.position.icrs) else: log.warning( f"Skipping model {model.name} - no spatial component present" ) return SkyCoord(positions)
[docs] def to_regions(self): """Returns a list of the regions for the spatial models Returns ------- regions: list of `~regions.SkyRegion` Regions """ regions = [] for model in self.select(tag="sky-model"): try: region = model.spatial_model.to_region() regions.append(region) except AttributeError: log.warning( f"Skipping model {model.name} - no spatial component present" ) return regions
@property def wcs_geom(self): """Minimum WCS geom in which all the models are contained""" regions = self.to_regions() try: return RegionGeom.from_regions(regions).to_wcs_geom() except IndexError: log.error("No spatial component in any model. Geom not defined")
[docs] def plot_regions(self, ax=None, kwargs_point=None, path_effect=None, **kwargs): """Plot extent of the spatial models on a given wcs axis Parameters ---------- ax : `~astropy.visualization.WCSAxes` Axes to plot on. If no axes are given, an all-sky wcs is chosen using a CAR projection kwargs_point : dict Keyword arguments passed to `~matplotlib.lines.Line2D` for plotting of point sources path_effect : `~matplotlib.patheffects.PathEffect` Path effect applied to artists and lines. **kwargs : dict Keyword arguments passed to `~matplotlib.artists.Artist` Returns ------- ax : `~astropy.visualization.WcsAxes` WCS axes """ regions = self.to_regions() geom = RegionGeom.from_regions(regions=regions) return geom.plot_region( ax=ax, kwargs_point=kwargs_point, path_effect=path_effect, **kwargs )
[docs] def plot_positions(self, ax=None, **kwargs): """ "Plot the centers of the spatial models on a given wcs axis Parameters ---------- ax : `~astropy.visualization.WCSAxes` Axes to plot on. If no axes are given, an all-sky wcs is chosen using a CAR projection **kwargs : dict Keyword arguments passed to `~matplotlib.pyplot.scatter` Returns ------- ax : `~astropy.visualization.WcsAxes` Wcs axes """ from astropy.visualization.wcsaxes import WCSAxes if ax is None or not isinstance(ax, WCSAxes): ax = Map.from_geom(self.wcs_geom).plot() kwargs.setdefault("marker", "*") kwargs.setdefault("color", "tab:blue") path_effects = kwargs.get("path_effects", None) xp, yp = self.positions.to_pixel(ax.wcs) p = ax.scatter(xp, yp, **kwargs) if path_effects: plt.setp(p, path_effects=path_effects) return ax
[docs]class Models(DatasetModels, collections.abc.MutableSequence): """Sky model collection. Parameters ---------- models : `SkyModel`, list of `SkyModel` or `Models` Sky models """ def __delitem__(self, key): del self._models[self.index(key)] def __setitem__(self, key, model): from gammapy.modeling.models import FoVBackgroundModel, SkyModel if isinstance(model, (SkyModel, FoVBackgroundModel)): self._models[self.index(key)] = model else: raise TypeError(f"Invalid type: {model!r}")
[docs] def insert(self, idx, model): if model.name in self.names: raise (ValueError("Model names must be unique")) self._models.insert(idx, model)
class restore_models_status: def __init__(self, models, restore_values=True): self.restore_values = restore_values self.models = models self.values = [_.value for _ in models.parameters] self.frozen = [_.frozen for _ in models.parameters] self.covariance_data = models.covariance.data def __enter__(self): pass def __exit__(self, type, value, traceback): for value, par, frozen in zip(self.values, self.models.parameters, self.frozen): if self.restore_values: par.value = value par.frozen = frozen self.models.covariance = self.covariance_data