add_node - adds a disconnected node to a graph
add_node adds a disconnected node to graph g and returns the new graph g1.
The coordinates of the new node can be given as a row vector of coordinates in xy. If the nodes of graph g have no coordinates (elements node_x and node_y are []), to give xy has no effect. If the nodes of graph g have coordinates and xy is not given, the new node has (0,0) as coordinates.
If name is given, it is the name of the new node, otherwise the number of nodes plus 1 is taken as the name of the new node.
ta=[1 1 2 2 2 3 4 5 5 7 8 8 9 10 10 10 11 12 13 13 13 14 15 16 16 17 17];
he=[2 10 3 5 7 4 2 4 6 8 6 9 7 7 11 15 12 13 9 10 14 11 16 1 17 14 15];
g=make_graph('foo',1,17,ta,he);
g('node_x')=[283 163 63 57 164 164 273 271 339 384 504 513 439 623 631 757 642];
g('node_y')=[59 133 223 318 227 319 221 324 432 141 209 319 428 443 187 151 301];
show_graph(g);
n=g('node_number');
g1=add_node(g,[270 140]);
g1('node_color')=[ones(1,n) 11];
show_graph(g1);