Source code for pysm.sky

""" This submoduls contains most of the user-facing code, as the objects
`Sky` and `Instrument` can be used for most of the functionality of the
code, without delving into the difference `Model` objects.

Objects:
    Sky
"""
import toml
import numpy as np
from astropy.utils import data
from . import units as u
from .utils import normalize_weights, bandpass_unit_conversion

from .constants import DATAURL
from .models import (
    Model,
    ModifiedBlackBody,
    DecorrelatedModifiedBlackBody,
    PowerLaw,
    SpDust,
    SpDustPol,
)


def remove_class_from_dict(d):
    """Return a copy of dictionary without the key "class" """
    return {k: d[k] for k in d.keys() if k != "class"}


def create_components_from_config(config, nside, map_dist=None):
    output_components = []
    for model_name, model_config in config.items():
        try:
            class_name = model_config["class"]
        except KeyError:  # multiple components
            partial_components = []
            for each_config in model_config.values():
                class_name = each_config["class"]
                component_class = globals()[class_name]
                partial_components.append(
                    component_class(
                        **remove_class_from_dict(each_config),
                        nside=nside,
                        map_dist=map_dist
                    )
                )
            output_component = Sky(
                component_objects=partial_components, nside=nside, map_dist=map_dist
            )
        else:
            component_class = globals()[class_name]
            output_component = component_class(
                **remove_class_from_dict(model_config), nside=nside, map_dist=map_dist
            )
        output_components.append(output_component)
    return output_components


with data.conf.set_temp("dataurl", DATAURL):
    PRESET_MODELS = toml.load(data.get_pkg_data_filename("data/presets.cfg"))


[docs]class Sky(Model): """ This class is a convenience object that wraps together a group of component models. It acts like a single `pysm.Model` object, in that it is sub-classed from the `pysm.Model` template, and therefore has the same functionality. Attributes ---------- components: list(pysm.Model object) List of `pysm.Model` objects. """ def __init__( self, nside=None, component_objects=None, component_config=None, preset_strings=None, output_unit=u.uK_RJ, map_dist=None, ): if nside is None and not component_objects: # not None and not [] raise Exception("Need to specify nside in Sky") elif nside is None: nside = component_objects[0].nside elif component_objects: for comp in component_objects: assert ( nside == comp.nside ), "Component objects should have same NSIDE of Sky" super().__init__(nside=nside, map_dist=map_dist) self.components = component_objects if component_objects is not None else [] # otherwise instantiate the sky object from list of predefined models, # identified by their strings. These are defined in `pysm.presets`. if component_config is None: component_config = {} elif not isinstance(component_config, dict): component_config = toml.load(component_config) if preset_strings is not None: assert isinstance(preset_strings, list), "preset_strings should be a list" for string in preset_strings: component_config[string] = PRESET_MODELS[string] if len(component_config) > 0: self.components += create_components_from_config( component_config, nside=nside, map_dist=map_dist ) self.output_unit = u.Unit(output_unit)
[docs] def add_component(self, component): self.components.append(component)
[docs] def get_emission(self, freq, weights=None): """ This function returns the emission at a frequency, set of frequencies, or over a bandpass. """ output = self.components[0].get_emission(freq, weights=weights) for comp in self.components[1:]: output += comp.get_emission(freq, weights=weights) return output * bandpass_unit_conversion(freq, weights, self.output_unit)