# Licensed under a 3-clause BSD style license - see LICENSE.rst
"""Source catalog and object base classes."""
import abc
import numbers
from copy import deepcopy
import numpy as np
from astropy.coordinates import SkyCoord
from astropy.utils import lazyproperty
from gammapy.maps import TimeMapAxis
from gammapy.modeling.models import Models
from gammapy.utils.table import table_from_row_data, table_row_to_dict
__all__ = ["SourceCatalog", "SourceCatalogObject"]
# https://pydanny.blogspot.com/2011/11/loving-bunch-class.html
class Bunch(dict):
def __init__(self, **kw):
dict.__init__(self, kw)
self.__dict__.update(kw)
def format_flux_points_table(table):
for column in table.colnames:
if column.startswith(("dnde", "eflux", "flux", "e2dnde", "ref")):
table[column].format = ".3e"
elif column.startswith(
("e_min", "e_max", "e_ref", "sqrt_ts", "norm", "ts", "stat")
):
table[column].format = ".3f"
return table
[docs]class SourceCatalogObject:
"""Source catalog object.
This class can be used directly, but it is mostly used as a
base class for the other source catalog classes.
The catalog data on this source is stored in the `source.data`
attribute as a dict.
The source catalog object is decoupled from the source catalog,
it doesn't hold a reference back to it, except for a key
``_row_index`` of type ``int`` that links to the catalog table
row the source information comes from.
"""
_source_name_key = "Source_Name"
_row_index_key = "_row_index"
def __init__(self, data, data_extended=None):
self.data = Bunch(**data)
if data_extended:
self.data_extended = Bunch(**data_extended)
@property
def name(self):
"""Source name (str)"""
name = self.data[self._source_name_key]
return name.strip()
@property
def row_index(self):
"""Row index of source in catalog (int)"""
return self.data[self._row_index_key]
@property
def position(self):
"""Source position (`~astropy.coordinates.SkyCoord`)."""
table = table_from_row_data([self.data])
return _skycoord_from_table(table)[0]
[docs]class SourceCatalog(abc.ABC):
"""Generic source catalog.
This class can be used directly, but it is mostly used as a
base class for the other source catalog classes.
This is a thin wrapper around `~astropy.table.Table`,
which is stored in the ``catalog.table`` attribute.
Parameters
----------
table : `~astropy.table.Table`
Table with catalog data.
source_name_key : str
Column with source name information
source_name_alias : tuple of str
Columns with source name aliases. This will allow accessing the source
row by alias names as well.
"""
[docs] @classmethod
@abc.abstractmethod
def description(cls):
"""Catalog description (str)."""
pass
source_object_class = SourceCatalogObject
"""Source class (`SourceCatalogObject`)."""
def __init__(self, table, source_name_key="Source_Name", source_name_alias=()):
self.table = table
self._source_name_key = source_name_key
self._source_name_alias = source_name_alias
def __str__(self):
return (
f"{self.__class__.__name__}:\n"
f" name: {self.name}\n"
f" description: {self.description}\n"
f" sources: {len(self.table)}\n"
)
@lazyproperty
def _name_to_index_cache(self):
# Make a dict for quick lookup: source name -> row index
names = {}
for idx, row in enumerate(self.table):
name = row[self._source_name_key]
names[name.strip()] = idx
for alias_column in self._source_name_alias:
for alias in str(row[alias_column]).split(","):
if not alias == "":
names[alias.strip()] = idx
return names
[docs] def row_index(self, name):
"""Look up row index of source by name.
Parameters
----------
name : str
Source name
Returns
-------
index : int
Row index of source in table
"""
index = self._name_to_index_cache[name]
row = self.table[index]
# check if name lookup is correct other wise recompute _name_to_index_cache
possible_names = [row[self._source_name_key]]
for alias_column in self._source_name_alias:
possible_names += str(row[alias_column]).split(",")
if name not in possible_names:
self.__dict__.pop("_name_to_index_cache")
index = self._name_to_index_cache[name]
return index
[docs] def source_name(self, index):
"""Look up source name by row index.
Parameters
----------
index : int
Row index of source in table
"""
source_name_col = self.table[self._source_name_key]
name = source_name_col[index]
return name.strip()
def __getitem__(self, key):
"""Get source by name.
Parameters
----------
key : str or int
Source name or row index
Returns
-------
source : `SourceCatalogObject`
An object representing one source
"""
if isinstance(key, str):
index = self.row_index(key)
elif isinstance(key, numbers.Integral):
index = key
elif isinstance(key, np.ndarray) and key.dtype == bool:
new = deepcopy(self)
new.table = self.table[key]
return new
else:
raise TypeError(f"Invalid key: {key!r}, {type(key)}\n")
return self._make_source_object(index)
def _make_source_object(self, index):
"""Make one source object.
Parameters
----------
index : int
Row index
Returns
-------
source : `SourceCatalogObject`
Source object
"""
data = table_row_to_dict(self.table[index])
data[SourceCatalogObject._row_index_key] = index
hist_table = getattr(self, "hist_table", None)
hist2_table = getattr(self, "hist2_table", None)
if hist_table:
data["time_axis"] = TimeMapAxis.from_table(hist_table, format="fermi-fgl")
if hist2_table:
data["time_axis_2"] = TimeMapAxis.from_table(
hist2_table, format="fermi-fgl"
)
if "Extended_Source_Name" in data:
name_extended = data["Extended_Source_Name"].strip()
elif "Source_Name" in data:
name_extended = data["Source_Name"].strip()
else:
name_extended = None
try:
idx = self._lookup_extended_source_idx[name_extended]
data_extended = table_row_to_dict(self.extended_sources_table[idx])
except (KeyError, AttributeError):
data_extended = None
source = self.source_object_class(data, data_extended)
return source
@lazyproperty
def _lookup_extended_source_idx(self):
names = [_.strip() for _ in self.extended_sources_table["Source_Name"]]
idx = range(len(names))
return dict(zip(names, idx))
@property
def positions(self):
"""Source positions (`~astropy.coordinates.SkyCoord`)."""
return _skycoord_from_table(self.table)
[docs] def to_models(self, **kwargs):
"""Create Models object from catalogue"""
return Models([_.sky_model(**kwargs) for _ in self])
def _skycoord_from_table(table):
keys = table.colnames
if {"RAJ2000", "DEJ2000"}.issubset(keys):
lon, lat, frame = "RAJ2000", "DEJ2000", "icrs"
elif {"RA", "DEC"}.issubset(keys):
lon, lat, frame = "RA", "DEC", "icrs"
elif {"ra", "dec"}.issubset(keys):
lon, lat, frame = "ra", "dec", "icrs"
else:
raise KeyError("No column GLON / GLAT or RA / DEC or RAJ2000 / DEJ2000 found.")
unit = table[lon].unit.to_string() if table[lon].unit else "deg"
return SkyCoord(table[lon], table[lat], unit=unit, frame=frame)