示例#1
0
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
示例#2
0
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
示例#3
0
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
示例#4
0
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
示例#5
0
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
示例#6
0
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