Assign Numerical Node Labels

I am working with a digraph GG. I need to label the nodes in a different order than the order in which they appear in the adjacency matrix which was used to generate GG. I have these new integer-valued labels in a Nx1 vector called Name (N is the number of nodes). Why is it that I get an error when I use the following command?

>> GG.Nodes.Name = num2str(Name).

I also tried

>> labelnode(GG, 1:N, num2str(Name)),

again, to no avail.

Thank you very much for any advice you can offer.

[Christine Tobler]

Can you tell us the error message you're getting?

Answer 1

[Christine Tobler]

For the first call, use

>> GG.Nodes.Name = num2str(Name)'

- GG.Nodes.Name has to be a column vector.

For the second call, labelnode only applies labels to a plot of a graph, not to the graph itself. For example

p = plot(GG);
labelnode(p, 1:26, num2str(Name));

But this is usually used to just relabel one or a few of the nodes. To set all of their labels in the plot (but not in the graph object), you would use

plot(GG, 'NodeLabel', num2str(Name));

[Kamal Premaratne]

Oops, now I realize the mistake I did. I used

num2str(Name')

which generates a row vector instead of

num2str(Name)'

which generates the correct column vector.

Also, good to know the difference between creating a Name column in the Node table and labelnode.

Thank you very much for all your help.

Answer 2

[Kamal Premaratne]

Thanks for the response. Here are the messages:

>> GG.Nodes.Name = num2str(Name)

Error using digraph.validateNodeProperties (line 341)

Name variable in node table must have one column.

Error in digraph/set.Nodes (line 312)

G.NodeProperties = digraph.validateNodeProperties(T);

Error in digraph/subsasgn (line 52)

G = builtin('subsasgn', G, S, V);

>> labelnode(GG, 1:26, num2str(Name)) % N = 26

Check for missing argument or incorrect argument data type in call to function 'labelnode'.

[Kamal Premaratne]

Hi Christine:

If I may, I would like to follow-up on my question and your response. For this discussion, let me create a simple 4-vertex / 4-edge weighted digraph:

>> start_node = [1 2 3 4]; end_node = [2 3 4 2]; edge_weight = [1 2 3 4];

>> G = digraph(start_node, end_node, edge_weight);

Everything is fine so far. Suppose I want to relabel the default vertex labels [1 2 3 4] to [2 3 4 5]:

>> new_labels = [2 3 4 5]'; % Notice that this is a column vector.

Now I would like to enter this information into the node table as a new column:

>> G.Nodes.Name = num2str(new_labels)

MATLAB does not like this and it spits out the following error.

_____BEGIN_____

Error using digraph.validateName (line 352)

Node names must be a string vector or a cell array of character vectors.

Error in digraph.validateNodeProperties (line 343)

T.Name = digraph.validateName(name);

Error in digraph/set.Nodes (line 312)

G.NodeProperties = digraph.validateNodeProperties(T);

Error in digraph/subsasgn (line 52)

G = builtin('subsasgn', G, S, V);

_____END____

Do you know why? Thank you.