def k_skip_graph(G,cover,k):
H = nx.Graph()
s1=time.time()
for node in cover:
G2 = share.vincity(G,node,k)
SPT = share.SPT(G2,node)
SPTD = nx.single_source_dijkstra_path_length(SPT,node)
tmp = [node]
picked = []
while(len(tmp)>0):
x = tmp.pop()
picked.append(x)
for u in SPT.neighbors(x):
if u in picked:
continue
if u in cover and u != node:
H.add_edge(node,u)
H[node][u]['weight'] = SPTD[u]
else:
tmp.insert(0,u)
# print '..............................................'
t1 = time.time()
print '%.4f sec -- kG construct finished' %(t1-s1)
return H
def sampling(G,cent,hop,cover): G2 = share.vincity(G,cent,hop) sp = nx.single_source_dijkstra(G2,cent) for path in sp[1].values(): if len(path) >= hop: if len(set(path) & set(cover))==0: return True return False
def local_query_edit(G,start,end,cover,k):
G2 = share.vincity(G,start,k)
sp = nx.single_source_dijkstra(G2,start)
n_set = {}
loc_dist = -1
if end in sp[1]:
loc_dist = sp[0][end]
for path in sp[1].values():
tmp = list(set(path[1:])&set(cover))
if len(tmp)>0:
tmp = tmp[0]
if tmp not in n_set:
n_set[tmp] = sp[0][tmp]
return [n_set,loc_dist]
def k_skip_graph(G,cover,k):
cover_tmp = [i for i in cover]
H = nx.Graph()
while(len(cover_tmp) >0):
cent = cover_tmp[0]
cover_tmp.remove(cent)
dist={}; dist[cent]=[0,0,0]
picked = []
while( len(dist) >0):
u = share.pick_min_Key_edit(dist)
G2 = share.vincity(G,u,k)
picked.append(u)
if u in cover and u != cent and dist[u][2] == 0:
H.add_edge(cent,u)
H[cent][u]['weight']=dist[u][0]
dist[u][2] = 1
if dist[u][1] < k:
share.find_neighbors_edit2(G2,u,dist,picked)
del dist[u]
return H
