Hello,
I understand from your question that you are plotting a graph and want to remove some branches randomly. Since you have a fixed number of nodes and node coordinates you don't want to remove the nodes, which results in the error.
Since you have fixed node coordinates, you can specify beforehand the total number of nodes. This can be done by specifying when graph object is created as below:
G=graph(b(:,1)',b(:,2)',b(:,3)',total_nodes);
The extra nodes are disconnected from the primary connected component.
For more information on creating the graph object using the above argument you can refer to the documentation under the section Edge List Construction with Extra Nodes. The documentation link refers to R2021a release but will work for R2015b release as well.
If you would like to refer to archived documentation, you can access it from the following link: https://www.mathworks.com/help/doc-archives.html .
For access to earlier releases, please contact support.
