min_weight_tree for non oriented graph

[Pierre-Alain Millet]

   thanks for any help to a newbie, in a learning phase on a simple  
example...  ;o-)

using the min_weight_tree function with a non oriented graph, i do not  
understand the result, and for my understanding, the result is not a  
tree...

before creating a request or bug, i imagine someone can explain more...

Example:

ta=[ 1, 1, 1, 2, 2, 2, 3, 4, 5, 8, 7, 6, 6, 6, 6, 6, 9, 9,10,11,12,13,14];
he=[ 2,10,11, 3, 7, 8, 4, 5, 8, 7, 6,11,12,13,14,15,11,10,11,12,13,14,15];
g=make_graph('name',0,15,ta,he);
t=min_weight_tree(1,g);
for i=1:(node_number(g)-1)
        arbre(i,1)=g.tail(t(i));
        arbre(i,2)=g.head(t(i));
end

-->arbre
arbre  =

    1.     2.
    2.     3.
    4.     5.
    5.     8.
    6.     11.
    2.     7.
    2.     8.
    9.     10.
    1.     10.
    1.     11.
    11.    12.
    6.     13.
    6.     14.
    6.     15.

For me, in a tree, the root is the only node with no head ...
in this example: 1,4,6,9... that is a forest !

so the result of min_weight_tree is not a tree ?

i read and read again the help with this strange sentence

If  T(I)  is the root of the tree:
- for j < i,  T(J)  is the number of the arc in the tree after node  T(J)
- for j > i,  T(J)  is the number of the arc in the tree before node  T(J)

   t(j) is not a node... so what means "after node  T(J)" and   
before node  T(J) ??

   so i suppose there is an error in this documentation...

   again, thanks for any help

   pam

   pam


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