How to plot a weighted graph?

for example: How to plot bellow graph?

G=[1 4 0.2
2 4 0.2
3 4 0.2
4 1 0.7
4 2 0.7
4 3 0.7
4 5 0.5
4 8 0.6
5 4 0.4
5 6 0.8
5 7 0.8
6 5 0.3
7 5 0.3
8 4 0.5
8 9 0.9
8 10 0.9
8 11 0.9
9 8 0.4
10 8 0.4
11 8 0.5
11 12 0.6
12 11 0.2];

and How to plot an unweighted graph?

[Azzi Abdelmalek]

What is unweighted graph?

[Muhammad Usman Saleem]

also what is weighted graph? I know about weight mean not weighted graph

[Walter Roberson]

"A weight is a numerical value, assigned as a label to a vertex or edge of a graph. A weighted graph is a graph whose vertices or edges have been assigned weights; more specifically, a vertex-weighted graph has weights on its vertices and an edge-weighted graph has weights on its edges."

For example, if you were creating a pipeline network, then the weight might correspond to the carrying capacity of the pipe. If you were creating a road map, then the weight might correspond to the speed limit on the segment.

Answer 1

[Mike Garrity]

Something like this?

G=[1 4 0.2; ...
   2 4 0.2; ...
   3 4 0.2; ...
   4 1 0.7; ...
   4 2 0.7; ...
   4 3 0.7; ...
   4 5 0.5; ...
   4 8 0.6; ...
   5 4 0.4; ...
   5 6 0.8; ...
   5 7 0.8; ...
   6 5 0.3; ...
   7 5 0.3; ...
   8 4 0.5; ...
   8 9 0.9; ...
   8 10 0.9; ...
   8 11 0.9; ...
   9 8 0.4; ...
  10 8 0.4; ...
  11 8 0.5; ...
  11 12 0.6; ...
  12 11 0.2];
g = digraph(G(:,1),G(:,2),G(:,3));
plot(g,'EdgeLabel',g.Edges.Weight)

Requires R2015b. Do 'help digraph' to get more examples. You can do things like color the edges by the weights.

[Muhammad Usman Saleem]

I think g.Edges.Weight is bolding Edges of g? @Mike Garrity

[Walter Roberson]

I do not understand what you mean by "bolding" in that question?

[Jack Ie]

It works in R2015b. how to do this in R2014b?

[Mike Garrity]

Sorry, graph was introduced in R2015b.

[Steven Lord]

To "bold" all the edges (which I interpreted as making those with higher weight appear wider/thicker) use the LineWidth property.

plot(g,'EdgeLabel',g.Edges.Weight, 'LineWidth', 5*g.Edges.Weight)

If you want to change only the width of certain edges, say those with the highest weights, look instead at highlight.

% Plot the graph and increase the size of the arrows
% This will let us see the arrows more easily after highlighting
h = plot(g,'EdgeLabel',g.Edges.Weight, 'ArrowSize', 15);

% Locate the indices of the edges with the highest weights
edgesHighestWeight = find(g.Edges.Weight == max(g.Edges.Weight));

% Convert those indices into source and target nodes
[S, T] = findedge(g, edgesHighestWeight);

% Highlight the edges (S, T) where S and T are vectors of node indices
highlight(h, S, T, 'LineWidth', 5);

For this example only the three edges (8, 11), (8, 9), and (8, 10) should be highlighted. They're the only ones with weight 0.9.

[sibabalo noludwwe]

if I want my graph to be weighted on the vertices instead of weighting the edges what do I do?

[Steven Lord]

Change the MarkerSize property of the object returned by plot, either in the call to plot itself (like LineWidth in the first line of code in my message from April 6th 2016) or afterwards (for this you can use highlight like I did in the last line of code in my message, but specifying MarkerSize instead of LineWidth.)

[Luara Antunes]

How to plot a weighted graph when the vertex-weighted graph has weights on its vertices, but not in edge-weighted?

[Steven Lord]

Add a property to the Nodes table as shown on this documentation page.

[Luara Antunes]

Thanks

Answer 2

[Walter Roberson]

In the File Exchange there are http://www.mathworks.com/matlabcentral/fileexchange/24035-wgplot-weighted-graph-plot--a-better-version-of-gplot- and http://www.mathworks.com/matlabcentral/fileexchange/4266-grtheory-graph-theory-toolbox

[Muhammad Usman Saleem]

thanks for sharing!

[Joel Sande]

Hi, How to include digraph folder in Matlab 2014a ? thanks

[Joel Sande]

I downloaded the folder digraph. I don t know how to use it in my code. I have the 2014a version.