-->m1 = rand(5,5)
 m1  =
 
    0.2113249    0.6283918    0.5608486    0.2320748    0.3076091  
    0.7560439    0.8497452    0.6623569    0.2312237    0.9329616  
    0.0002211    0.6857310    0.7263507    0.2164633    0.2146008  
    0.3303271    0.8782165    0.1985144    0.8833888    0.312642   
    0.6653811    0.0683740    0.5442573    0.6525135    0.3616361  
 
-->m2=m1+0.5
 m2  =
 
    0.7113249    1.1283918    1.0608486    0.7320748    0.8076091  
    1.2560439    1.3497452    1.1623569    0.7312237    1.4329616  
    0.5002211    1.185731     1.2263507    0.7164633    0.7146008  
    0.8303271    1.3782165    0.6985144    1.3833888    0.812642   
    1.1653811    0.5683740    1.0442573    1.1525135    0.8616361  
 
-->m3=fix(m2)
 m3  =
 
    0.    1.    1.    0.    0.  
    1.    1.    1.    0.    1.  
    0.    1.    1.    0.    0.  
    0.    1.    0.    1.    0.  
    1.    0.    1.    1.    0.  
 
-->m4=triu(m3,1)
 m4  =
 
    0.    1.    1.    0.    0.  
    0.    0.    1.    0.    1.  
    0.    0.    0.    0.    0.  
    0.    0.    0.    0.    0.  
    0.    0.    0.    0.    0.  
 
-->a=m4 + m4'
 a  =
 
    0.    1.    1.    0.    0.  
    1.    0.    1.    0.    1.  
    1.    1.    0.    0.    0.  
    0.    0.    0.    0.    0.  
    0.    1.    0.    0.    0.  
 
-->// number of vertices
 
-->[n, junk]=size(a);
 
-->n
 n  =
 
    5.  
 
-->// number of edges
 
-->e = sum(a)/2
 e  =
 
    4.  
 
-->// degree sequence
 
-->sort(sum(a, 'r'))
 ans  =
 
    3.    2.    2.    1.    0.  
 
-->//eigenvalues of the graph
 
-->spec(a)
 ans  =
 
  - 1.4811943  
  - 1.         
    0.         
    0.3111078  
    2.1700865  
 
-->eigs(a)
        !--error 4 
undefined variable : eigs                    
 
 
-->// put it into the graph theory form
 
-->sparse(a)
 ans  =
 
(    5,    5) sparse matrix
 
(    1,    2)        1. 
(    1,    3)        1. 
(    2,    1)        1. 
(    2,    3)        1. 
(    2,    5)        1. 
(    3,    1)        1. 
(    3,    2)        1. 
(    5,    2)        1. 
 
-->g = mat_2_graph(sparse(a), 0, 'node-node');
 
-->i = 0:1:4
 i  =
 
    0.    1.    2.    3.    4.  
 
-->t = i .* 2*%pi/5
 t  =
 
    0.    1.2566371    2.5132741    3.7699112    5.0265482  
 
-->g('node_x') = 100*cos(t);
 
-->g('node_y') = 100*sin(t);
 
-->show_graph(g);
 
-->xs2eps(0,'may18.eps');
 
-->plot_graph(g);
 
-->graph_diameter(g)
 ans  =
 
    1.000E+09  
 
-->h=graph_complement(g);
 
-->graph_diameter(h)
 ans  =
 
    2.  
 
-->hamilton(h)
 !--error 9999 
The graph must be directed                                                      
at line       9 of function hamilton called by :  
hamilton(h)
 
 
-->// Draw K_3,3
 
-->tail = [ 1 1 1 2 2 2 3 3 3]; head = [4 5 6 4 5 6 4 5 6];
 
-->k33=make_graph('k_3,3', 0, tail, head);
 !--error 39 
incorrect number of arguments
at line       4 of function make_graph called by :  
k33=make_graph('k_3,3', 0, tail, head);
 
 
-->k33=make_graph('k_3,3', 0, 6, tail, head);
 
-->k33('node_x') = [ 100 100 100 300 300 300];
 
-->k33('node_y') = [ 100 200 300 100 200 300];
 
-->show_graph(k33);
 
-->diary(0);