Re: [igraph] How to get weight after loading ncol file

[Tamas Nepusz]

> I am loading a weighted graph from an ncol file. I want to access  
> the weights for usage in the walktrap function. Do i have to use  
> iterators and fill a vector with the values or is there something  
> more straight forward I can do.
Take a look at the igraph_cattribute_table structure that you use to  
initialize the C attribute handler interface. There's a member called  
get_numeric_edge_attr with the following signature:

int (*get_numeric_edge_attr)(const igraph_t *graph, const char *name,  
igraph_es_t es, igraph_vector_t *value);
This can be used to retrieve a given attribute of multiple edges at  
the same time to an igraph vector as follows (untested):

igraph_cattribute_table.get_numeric_edge_attr(your_graph, "weight",  
igraph_ess_all(), your_vector);

--
T.