I would like to get a subgraph around a specific node of a a directed graph based on the out_edges or in_edges only.
# This does not work
H_tmp = nx.ego_graph(G, node_name, 2)
H_tmp.out_edges = []
H = nx.ego_graph(H_tmp, node_name, 2)
I tried using nx.ego_graph twice, but I don't know an efficient way to remove all the out_edges or in_edges. Is there a way to tell ego_graph to use only a specific set of edges?
Using the eco_graph function on an undirected graph extracts the out successors of the node. According to the doc, if you only want the predecessors (in_edges), you can apply the eco_graph function on the reverse of your graph. You'll then need to reverse your subgraph. If you want both successors and predecessors, you can specify undirected=True. See example summarizing this below:
import networkx as nx
import matplotlib.pyplot as plt
H = nx.fast_gnp_random_graph(5, 0.3,directed=True)
plt.figure(figsize=(15,10))
plt.subplot(141)
plt.title('Full graph')
nx.draw(H,with_labels=True)
plt.subplot(142)
plt.title('All neighbors around node 2')
H_all=nx.ego_graph(H, 2, 1,undirected=True)
nx.draw(H_all,with_labels=True)#plot
plt.subplot(143)
plt.title('Out subgraph around node 2')
H_out=nx.ego_graph(H, 2, 1)
nx.draw(H_out,with_labels=True) #plot
plt.subplot(144)
plt.title('In subgraph around node 2')
H_in=nx.ego_graph(H.reverse(), 2, 1) #apply eco_graph to reverse graph to get in_edges
H_in_r=H_in.reverse() #reverse subgraph
nx.draw(H_in_r,with_labels=True) #plot
I am learning the networkx function named "networkx.graph_edit_distance(g2,q)". Actually, GED(g2,q) = 2.If we want to tranform g2 to q, we should do at least 2 graph edit operations"substituing (1,3) whose label is '2' in g2 to (1,3) whose label is '1', inserting (3,4) which is not exsits in g2 to (3,4) whose label
is '1".My code is shown below:
nodes = [(1,{'label':'C1'}),
(2,{'label':'C2'}),
(3,{'label':'C3'}),
(4,{'label':'C4'}),
(5,{'label':'N'})]
edges = [(1,2,{'label':'1'}),
(2,4,{'label':'1'}),
(4,5,{'label':'1'}),
(5,3,{'label':'1'}),
(3,1,{'label':'2'})]
g2 = nx.Graph()
g2.add_nodes_from(nodes)
g2.add_edges_from(edges)
nodes = [(1,{'label':'C1'}),
(2,{'label':'C2'}),
(3,{'label':'C3'}),
(4,{'label':'C4'}),
(5,{'label':'N'})]
edges = [(1,2,{'label':'1'}),
(2,4,{'label':'1'}),
(4,5,{'label':'1'}),
(5,3,{'label':'1'}),
(3,1,{'label':'1'}),
(3,4,{'label':'1'})]
q = nx.Graph()
q.add_nodes_from(nodes)
q.add_edges_from(edges)
GED_q_g2 = nx.graph_edit_distance(g2, q)
But unfortunately, the expected answer is GED =2， but it gives the answer GED_q_g2 = 1.Please how could I get the right answer?
When I look at the defined graph, the edit distance of 1 is correct, because only (3,4) needs to be removed.
The graph that you've drawn displays two edges between 1 and 3, though. I guess you've misunderstood the label functionality: It's just an optional data attribute that you can use for identification or plotting - it has nothing to do with the number of edges or weights.
If you want to use multiple edges between two nodes, have a look at nx.Multigraph.
just use the edge_match.
nx.graph_edit_distance(g1,g2,edge_match=lambda a,b: a['label'] == b['label']))
In Titan graph database, using gremlin, I want all the vertices whose out-degree is greater than 10.
How to do it?
Something like this doesn't work :
g.V().has(outE().count()>10)
Help please!!
You need something like this:
gremlin> graph = TinkerFactory.createModern()
==>tinkergraph[vertices:6 edges:6]
gremlin> g = graph.traversal()
==>graphtraversalsource[tinkergraph[vertices:6 edges:6], standard]
gremlin> g.V().filter(outE().count().is(gt(10)))
==>v[1]
==>v[4]
I'm doing a research about map projections. I use this script:
koordinat = [0 102;...
0 103.5;...
-1 103.5;...
-1 102];
lat = koordinat(:,1);
lon = koordinat(:,2);
mstruct = defaultm('utm');
mstruct.geoid = referenceEllipsoid('wgs84','meters');
mstruct.zone = utmzone(koordinat);
mstruct = defaultm(mstruct);
[x,y] = mfwdtran (mstruct,lat,lon);
format long g
luas = polyarea(x,y)
By using the "defaultm" and "mfwdtran" function, I can calculate the projected coordinate. Buut, my fellow researcher is feeling doubtful about these 2 Matlab functions. Do you know how to see the script of these two functions?
I already opened the defaultm.m and mfwdtran.m, but I didn't see anything like an m-file from mathworks.com called "deg2utm.m".
Any suggestion will helps.
Thank you
I want to use this command
r1 <- rPlot(y~x, color="z", data=my_df, type="tile")
It works, but I want the labels in the X-AXE to be perpendicular to the x-axe.
I can't find any material on the web about this.
I'm not sure about rPlot but when using plot() you can rotate them using las=.
Example:
r1 <- plot(x, y, main = "title", col = "blue", las=1)