def union(G, H):
"""
Return a new graph which is the simple union
of the node sets and edge sets.
Parameters
----------
G,H : Two undirected simple staticgraph
Returns
-------
GC: A new graph with the same type as G
Notes
-----
It is mandatory that G and H be both undirected.
The node sets of G and H must be same.
"""
if G.order() != H.order():
msg = "Node sets of the two undirected graphs are not equal!"
raise StaticGraphNotEqNodesException(msg)
edges = ((u, v) for u in G.nodes()
for v in chain(G.neighbours(u), H.neighbours(u)) if u < v)
deg = make_deg(G.order(), edges)
edges = ((u, v) for u in G.nodes()
for v in chain(G.neighbours(u), H.neighbours(u)) if u < v)
GC = make(G.order(), G.size() + H.size(), edges, deg)
return GC
def difference(G, H):
"""
Return a new graph that contains the edges that exist in G but not in H.
The node sets of H and G must be the same.
Parameters
----------
G,H : Two undirected simple staticgraphs
Returns
-------
D : A new graph with the same type as G.
Notes
-----
It is mandatory that G and H be both undirected.
The node sets of G and H must be same.
"""
if G.order() != H.order():
msg = "Node sets of the two undirected graphs are not equal!"
raise StaticGraphNotEqNodesException(msg)
edges = ((u, v) for u in G.nodes()
for v in set(G.neighbours(u)) - set(H.neighbours(u)) if u < v)
deg = make_deg(G.order(), edges)
edges = ((u, v) for u in G.nodes()
for v in set(G.neighbours(u)) - set(H.neighbours(u)) if u < v)
D = make(G.order(), G.size(), edges, deg)
return D
def union(G, H):
"""
Return a new graph which is the simple union
of the node sets and edge sets.
Parameters
----------
G,H : Two undirected simple staticgraph
Returns
-------
GC: A new graph with the same type as G
Notes
-----
It is mandatory that G and H be both undirected.
The node sets of G and H must be same.
"""
if G.order() != H.order():
msg = "Node sets of the two undirected graphs are not equal!"
raise StaticGraphNotEqNodesException(msg)
edges = ((u, v) for u in G.nodes()
for v in chain(G.neighbours(u), H.neighbours(u))
if u < v)
deg = make_deg(G.order(), edges)
edges = ((u, v) for u in G.nodes()
for v in chain(G.neighbours(u), H.neighbours(u))
if u < v)
GC = make(G.order(), G.size() + H.size(), edges, deg)
return GC
def complement(G):
"""
Returns the complement of Graph G
Parameters
----------
G : An undirected staticgraph
Returns
-------
H : A new staticgraph graph.
Notes
------
It is mandatory that G be undirected.
"""
nset = set(G.nodes())
n_nodes = G.order()
n_edges = n_nodes * (n_nodes - 1) / 2 - G.size()
cmp_edges = ((u, v) for u in G.nodes()
for v in nset - set(G.neighbours(u))
if u < v)
deg = make_deg(n_nodes, cmp_edges)
cmp_edges = ((u, v) for u in G.nodes()
for v in nset - set(G.neighbours(u))
if u < v)
H = make(n_nodes, n_edges, cmp_edges, deg)
return H
def difference(G, H):
"""
Return a new graph that contains the edges that exist in G but not in H.
The node sets of H and G must be the same.
Parameters
----------
G,H : Two undirected simple staticgraphs
Returns
-------
D : A new graph with the same type as G.
Notes
-----
It is mandatory that G and H be both undirected.
The node sets of G and H must be same.
"""
if G.order() != H.order():
msg = "Node sets of the two undirected graphs are not equal!"
raise StaticGraphNotEqNodesException(msg)
edges = ((u, v) for u in G.nodes()
for v in set(G.neighbours(u)) - set(H.neighbours(u))
if u < v)
deg = make_deg(G.order(), edges)
edges = ((u, v) for u in G.nodes()
for v in set(G.neighbours(u)) - set(H.neighbours(u))
if u < v)
D = make(G.order(), G.size(), edges, deg)
return D