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)