def graph_traveral(graph, start, threshold, method='bfs'):
"""
Given a graph, it provides graph traversal techniques including breadth-first search (bsf) and depth-first search (dfs) to explore hidden gene/tf associations.
-----------------------------------------------------------------------------
:param graph: network graph object.
:param start: str. starting point of graph.
:type start: str
:param threshold: int. the depth-limit
:param method: str. bfs or dfs
:return: explored graph.
"""
assert method in ['bfs', 'dfs'], 'valid method parameters: bfs, dfs!'
if method == 'bfs':
res_path = nextra.bfs_tree(graph, start, threshold)
elif method == 'dfs':
res_path = nextra.dfs_tree(graph, start, threshold)
return res_path
def elastic_centered_graph(self, start_node=None):
"""
Args:
start_node ():
Returns:
"""
logging.info("In elastic centering")
# Loop on start_nodes, sometimes some nodes cannot be elastically taken
# inside the cell if you start from a specific node
ntest_nodes = 0
start_node = list(self.graph.nodes())[0]
ntest_nodes += 1
centered_connected_subgraph = nx.MultiGraph()
centered_connected_subgraph.add_nodes_from(self.graph.nodes())
centered_connected_subgraph.add_edges_from(self.graph.edges(data=True))
tree = bfs_tree(G=self.graph, source=start_node)
current_nodes = [start_node]
nodes_traversed = [start_node]
inode = 0
# Loop on "levels" in the tree
tree_level = 0
while True:
tree_level += 1
logging.debug("In tree level {:d} ({:d} nodes)".format(tree_level, len(current_nodes)))
new_current_nodes = []
# Loop on nodes in this level of the tree
for node in current_nodes:
inode += 1
logging.debug(
" In node #{:d}/{:d} in level {:d} ({})".format(inode, len(current_nodes), tree_level, str(node))
)
node_neighbors = list(tree.neighbors(n=node))
node_edges = centered_connected_subgraph.edges(nbunch=[node], data=True, keys=True)
# Loop on neighbors of a node (from the tree used)
for inode_neighbor, node_neighbor in enumerate(node_neighbors):
logging.debug(
" Testing neighbor #{:d}/{:d} ({}) of node #{:d} ({})".format(
inode_neighbor,
len(node_neighbors),
node_neighbor,
inode,
node,
)
)
already_inside = False
ddeltas = []
for n1, n2, key, edata in node_edges:
if (n1 == node and n2 == node_neighbor) or (n2 == node and n1 == node_neighbor):
if edata["delta"] == (0, 0, 0):
already_inside = True
thisdelta = edata["delta"]
else:
if edata["start"] == node.isite and edata["end"] != node.isite:
thisdelta = edata["delta"]
elif edata["end"] == node.isite:
thisdelta = tuple([-dd for dd in edata["delta"]])
else:
raise ValueError("Should not be here ...")
ddeltas.append(thisdelta)
logging.debug(
" ddeltas : {}".format(
", ".join(["({})".format(", ".join(str(ddd) for ddd in dd)) for dd in ddeltas])
)
)
if ddeltas.count((0, 0, 0)) > 1:
raise ValueError("Should not have more than one 000 delta ...")
if already_inside:
logging.debug(" Edge inside the cell ... continuing to next neighbor")
continue
logging.debug(" Edge outside the cell ... getting neighbor back inside")
if (0, 0, 0) in ddeltas:
ddeltas.remove((0, 0, 0))
myddelta = np.array(ddeltas[0], np.int_)
node_neighbor_edges = centered_connected_subgraph.edges(
nbunch=[node_neighbor], data=True, keys=True
)
logging.debug(
" Delta image from node {} to neighbor {} : "
"{}".format(
str(node),
str(node_neighbor),
"({})".format(", ".join([str(iii) for iii in myddelta])),
)
)
# Loop on the edges of this neighbor
for n1, n2, key, edata in node_neighbor_edges:
if (n1 == node_neighbor and n2 != node_neighbor) or (
n2 == node_neighbor and n1 != node_neighbor
):
if edata["start"] == node_neighbor.isite and edata["end"] != node_neighbor.isite:
centered_connected_subgraph[n1][n2][key]["delta"] = tuple(
np.array(edata["delta"], np.int_) + myddelta
)
elif edata["end"] == node_neighbor.isite:
centered_connected_subgraph[n1][n2][key]["delta"] = tuple(
np.array(edata["delta"], np.int_) - myddelta
)
else:
raise ValueError("DUHH")
logging.debug(
" {} to node {} now has delta "
"{}".format(
str(n1),
str(n2),
str(centered_connected_subgraph[n1][n2][key]["delta"]),
)
)
new_current_nodes.extend(node_neighbors)
nodes_traversed.extend(node_neighbors)
current_nodes = new_current_nodes
if not current_nodes:
break
# Check if the graph is indeed connected if "periodic" edges (i.e. whose "delta" is not 0, 0, 0) are removed
check_centered_connected_subgraph = nx.MultiGraph()
check_centered_connected_subgraph.add_nodes_from(centered_connected_subgraph.nodes())
check_centered_connected_subgraph.add_edges_from(
[e for e in centered_connected_subgraph.edges(data=True) if np.allclose(e[2]["delta"], np.zeros(3))]
)
if not is_connected(check_centered_connected_subgraph):
raise RuntimeError("Could not find a centered graph.")
return centered_connected_subgraph
import networkx.generators.small import networkx as net import matplotlib.pyplot as plot from networkx.algorithms import traversal from networkx import algorithms g = networkx.generators.small.krackhardt_kite_graph() g.number_of_edges() g.number_of_nodes() g.adjacency_list() dict((x, g.neighbors(x)) for x in g.nodes()) # networkx.generators.small.krackhardt_kite_graph? net.draw(g) plot.show() edges=traversal.dfs_edges(g,0) list(edges) edges = traversal.bfs_edges(g, 0) bfs = list(edges) net.draw(traversal.bfs_tree(g,0)) plot.show() algorithms.shortest_path(g,0,7) shorts = algorithms.all_pairs_shortest_path(g) print "all shortest lengths", shorts
