MATLAB Answers


Question on using addedge()

Asked by Deepa Maheshvare on 14 Dec 2018
Latest activity Commented on by Steven Lord
on 14 Dec 2018
Accepted Answer by Jan
How do we use addedge to assign weights to a graph containing edges with multiple edge weigths(Value1 and Value2, in my example)?
tail = [1 2 3 4];
head = [2 3 4 5];
G = graph(tail,head)
G.Edges.Value1 = ones(4,1)
G.Edges.Value2 = zeros(4,1)
G = addedge(G,5,6,1) %I want to assign 1 to Value1 to the new edge created between nodes 5,6
I obtain the following error.
Error using graph/addedge (line 139)
Unable to add weighted edges to an unweighted graph.
Any suggestions?


on 14 Dec 2018
According to the documentation: doc addedge
H = addedge(G,s,t,w) also specifies weights, w, for the edges between s and t.
The 4th input is the weight. It is not clear to me, what "assign 1 to Value1" means.
I meant, assigning a value of 1 to the newly added edge in the edge property named Value1 (here->G.Edges.Value1 = ones(4,1))
Let's say the graph is weighted, then H = addedge(G,s,t,w) works for Graph.Edges.Weight.
I'm trying to do the same for custom attributes (Graph.Edges.Value1) and I couldn't succeed.
Hope I was able to explain the problem

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1 Answer

Answer by Jan
on 14 Dec 2018
Edited by Jan
on 14 Dec 2018
 Accepted Answer

Do you mean:
G = addedge(G,5,6)
G.Edges.Value1 = ones(5,1)
T = table(1, 0, 'VariableNames', {'Value1', 'Value2'});
G = addedge(G, 5, 6, T)

  1 Comment

Or you can build a table with variables EndNodes and your custom attribute names and call addedge with the graph and the table as the two inputs. The "Add Edges with Attributes to Graph" example on the addedge documentation page shows how to do this.

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