Source code for vermouth.processors.sort_molecule_atoms
# Copyright 2018 University of Groningen
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Provides a processor that sorts atoms within molecules.
"""
import copy
from functools import partial
from .processor import Processor
[docs]class SortMoleculeAtoms(Processor):
"""
Sort the atoms within a molecule by chain, resid, and resname.
This is usefull, for instance, when atoms have been added (*e.g.* missing
atoms identified by :class:`vermouth.processors.repair_graph.RepairGraph`).
The atom keys are left identical, only the order of the nodes is changed.
"""
[docs] def run_molecule(self, molecule):
node_order = sorted(molecule, key=partial(_keyfunc, molecule))
sorted_nodes = [
(node_key, molecule.nodes[node_key])
for node_key in node_order
]
edges = tuple(molecule.edges(data=True))
interactions = copy.copy(molecule.interactions)
molecule.remove_nodes_from(node_order)
molecule.add_nodes_from(sorted_nodes)
molecule.add_edges_from(edges)
molecule.interactions = interactions
return molecule
def _keyfunc(graph, node_idx):
"""
Reduce a molecule node to a tuple of chain, resid, and resname.
"""
# TODO add something like idx_in_residue
return (
graph.nodes[node_idx]['chain'],
graph.nodes[node_idx]['resid'],
graph.nodes[node_idx]['resname'],
)