MATLAB: Plotting an undirected graph gives me only unconnected dots.

Question

I have an undirected graph of 7618 edges that I want to plot. I put the first set of nodes of each edge in nodes1 and the other set of nodes of each edge in nodes2 and:

G= graph(nodes1,nodes2)
plot(G)

This is the plot I get

Why aren't the nodes connected like they are supposed to except from those in the bottom left? How do I fix it to get the results I want?

Matlab R2016a

Answer 1

I found a solution for deleting the isolated nodes. First you find the degree matrix for every node. The elements which have a degree of zero are isolated nodes. Therefore your next move is to find the indexes of those elements and the delete them from the graph:

D = degree(G);

index = find(D == 0);

D(index) = [];

G = rmnode(G,index);