"""
AncestryFilter functions
"""
#-----------------------------------------------------------------------------
# Copyright (c) ytree development team. All rights reserved.
#
# Distributed under the terms of the Modified BSD License.
#
# The full license is in the file COPYING.txt, distributed with this software.
#-----------------------------------------------------------------------------
import numpy as np
from yt.utilities.operator_registry import \
OperatorRegistry
ancestry_filter_registry = OperatorRegistry()
[docs]def add_ancestry_filter(name, function):
"""
Add an ancestry filter function to the registry.
"""
ancestry_filter_registry[name] = AncestryFilter(function)
[docs]class AncestryFilter(object):
r"""
An AncestryFilter takes a halo and a list of ancestors and
returns a filtered list of filtered list of ancestors. For
example, a filter could return only the most massive ancestor.
Parameters
----------
halo: halo data container
Data container of the descendent halo.
ancestors : list of halo data containers
List of data containers for the ancestor halos.
The function should return a list of data containers.
"""
[docs] def __init__(self, function, args=None, kwargs=None):
self.function = function
self.args = args
if self.args is None: self.args = []
self.kwargs = kwargs
if self.kwargs is None: self.kwargs = {}
def __call__(self, halo, ancestors):
return self.function(halo, ancestors, *self.args, **self.kwargs)
[docs]def most_massive(halo, ancestors):
r"""
Return only the most massive ancestor.
Parameters
----------
halo: halo data container
Data container of the descendent halo.
ancestors : list of halo data containers
List of data containers for the ancestor halos.
Returns
-------
filtered_ancestors : list of halo data containers
List containing data container of most massive halo.
"""
if len(ancestors) == 0: return []
i_max = np.argmax([my_halo.mass for my_halo in ancestors])
return [ancestors[i_max]]
add_ancestry_filter("most_massive", most_massive)