Re: [igraph] community_fastgreedy() requires integers as edge weights?

[Tamas Nepusz]

Hi Kurt,

> i've grabbed the dev version and re-installed python interface using  
> this:
>
> $ tla get address@hidden/igraph--main--0.5  
> igraph_dev
> ...
> $ python igraph_dev/interfaces/python setup.py install
Seems OK so far if you did the usual ./configure && make && sudo make  
install dance in the tree of the C core (otherwise the Python  
interface will still link to the old C core that was installed in /usr/ 
lib or /usr/local/lib or whatever).

> Seems ok and then when I try using weights w/ fast_greedy i get a  
> different error:
> [...]
> igraph.core.InternalError: Error at src/igraphmodule.c:1047:  
> Internal error, Invalid value
There are three causes in the fast greedy community routine that  
generates an "Invalid value" error message:
1. The weight vector is too short (quite unlikely in your case, since  
it comes from the edge attributes)
2. All weights must be positive - have you checked that?
3. A loop edge was detected - simplify the graph before starting the  
community detection.

If none of these applies to your case, then please send me a small  
dataset that reproduces the problem.

> Do i need to re-compile the development version of the C core?  If  
> so I'm a bit confused - where are the configure and make scripts?
There is a script called ./bootstrap.sh in the dev tree you checked  
out from our Arch repository which produces the configure script.  
You'll need automake and autoconf as well.

--
T.