# -*- coding: utf-8 -*-
"""Modules for creating and analysing energy system graphs.
This file is part of project oemof (github.com/oemof/oemof). It's copyrighted
by the contributors recorded in the version control history of the file,
available from its original location oemof/oemof/graph.py
SPDX-FileCopyrightText: Simon Hilpert <>
SPDX-FileCopyrightText: Uwe Krien <krien@uni-bremen.de>
SPDX-License-Identifier: MIT
"""
import warnings
import networkx as nx
[docs]def create_nx_graph(
energy_system=None,
remove_nodes=None,
filename=None,
remove_nodes_with_substrings=None,
remove_edges=None,
):
"""
Create a `networkx.DiGraph` for the passed energy system and plot it.
See https://networkx.org/documentation/ for more information.
Parameters
----------
energy_system : `oemof.solph.network.EnergySystem`
filename : str
Absolute filename (with path) to write your graph in the graphml
format. If no filename is given no file will be written.
remove_nodes: list of strings
Nodes to be removed e.g. ['node1', node2')]
remove_nodes_with_substrings: list of strings
Nodes that contain substrings to be removed e.g. ['elec', 'heat')]
remove_edges: list of string tuples
Edges to be removed e.g. [('resource_gas', 'gas_balance')]
Examples
--------
>>> import os
>>> import pandas as pd
>>> from oemof.network.network import Node
>>> from oemof.network.energy_system import EnergySystem
>>> import oemof.network.graph as grph
>>> datetimeindex = pd.date_range('1/1/2017', periods=3, freq='H')
>>> es = EnergySystem(timeindex=datetimeindex)
>>> b_gas = Node(label='b_gas')
>>> bel1 = Node(label='bel1')
>>> bel2 = Node(label='bel2')
>>> demand_el = Node(label='demand_el', inputs = [bel1])
>>> pp_gas = Node(label=('pp', 'gas'),
... inputs=[b_gas],
... outputs=[bel1])
>>> line_to2 = Node(label='line_to2', inputs=[bel1], outputs=[bel2])
>>> line_from2 = Node(label='line_from2',
... inputs=[bel2], outputs=[bel1])
>>> es.add(b_gas, bel1, demand_el, pp_gas, bel2, line_to2, line_from2)
>>> my_graph = grph.create_nx_graph(es)
>>> # export graph as .graphml for programs like Yed where it can be
>>> # sorted and customized. this is especially helpful for large graphs
>>> # grph.create_nx_graph(es, filename="my_graph.graphml")
>>> [my_graph.has_node(n)
... for n in ['b_gas', 'bel1', "('pp', 'gas')", 'demand_el', 'tester']]
[True, True, True, True, False]
>>> list(nx.attracting_components(my_graph))
[{'demand_el'}]
>>> sorted(list(nx.strongly_connected_components(my_graph))[1])
['bel1', 'bel2', 'line_from2', 'line_to2']
>>> new_graph = grph.create_nx_graph(energy_system=es,
... remove_nodes_with_substrings=['b_'],
... remove_nodes=["('pp', 'gas')"],
... remove_edges=[('bel2', 'line_from2')],
... filename='test_graph')
>>> [new_graph.has_node(n)
... for n in ['b_gas', 'bel1', "('pp', 'gas')", 'demand_el', 'tester']]
[False, True, False, True, False]
>>> my_graph.has_edge("('pp', 'gas')", 'bel1')
True
>>> new_graph.has_edge('bel2', 'line_from2')
False
>>> os.remove('test_graph.graphml')
Notes
-----
Needs graphviz and networkx (>= v.1.11) to work properly.
Tested on Ubuntu 16.04 x64 and solydxk (debian 9).
"""
with warnings.catch_warnings():
# suppress ExperimentalFeatureWarnungs
warnings.simplefilter("ignore")
# construct graph from nodes and flows
grph = nx.DiGraph()
# add nodes
for label in energy_system.node.keys():
grph.add_node(str(label), label=str(label))
# add labeled flows on directed edge if an optimization_model has been
# passed or undirected edge otherwise
for n in energy_system.nodes:
for i in n.inputs.keys():
weight = getattr(
energy_system.flows()[(i, n)], "nominal_value", None
)
if weight is None:
grph.add_edge(str(i.label), str(n.label))
else:
grph.add_edge(
str(i.label),
str(n.label),
weigth=format(weight, ".2f"),
)
# remove nodes and edges based on precise labels
if remove_nodes is not None:
grph.remove_nodes_from(remove_nodes)
if remove_edges is not None:
grph.remove_edges_from(remove_edges)
# remove nodes based on substrings
if remove_nodes_with_substrings is not None:
for i in remove_nodes_with_substrings:
remove_nodes = [
str(label)
for label in energy_system.node.keys()
if i in str(label)
]
grph.remove_nodes_from(remove_nodes)
if filename is not None:
if filename[-8:] != ".graphml":
filename = filename + ".graphml"
nx.write_graphml(grph, filename)
return grph