Re: [igraph] igraph 0.5 and Graph.Tree()

[Gábor Csárdi]

Marco,

On Fri, Jun 26, 2009 at 12:56 PM, Marco <address@hidden> wrote:

Hi Gabor,

what I don't understand is why, with always "directed 1", sometimes
plotting the graph results in directed graphs (with the almighty nice
arrows) and sometimes not, in the same machine.
Might it depend on the fact that when I see the directed graphs all
the nodes have attributes and when I see the undirected ones they have
not?

You will need to give us a reproducible example for this.
 

Also, I noticed that sometimes when I to a to_undirected() on one of
those graphs with attributes, I lose the attributes. Is this ok, or am
I seeing something not ok?

Not sometimes, but always. Yes, this was a known bug and was fixed some time ago.

igraph was installed using some rpm found on the net, of the 0.5
version for Fedora 8.

This is not very helpful, to be honest. Try installing the latest released version. Thanks.

Gabor
 

Thank you, as always,

My best,

marco
--
restituiremo il riso ai salici

On Fri, Jun 26, 2009 at 12:44 PM, Gábor Csárdi<address@hidden> wrote:
> Marco, this was not a bug, but I just followed the GML specification that
> said that directed is 1 for undirected graphs.
>
> In the current igraph version this is "corrected", directed is 1 for
> directed graphs. We made this change to be consistent with the many software
> packages that use GML format.
>
> Best,
> Gabor
>
> On Fri, Jun 26, 2009 at 12:35 PM, Marco <address@hidden> wrote:
>>
>> Hello all igraphers!
>>
>> I am using an old version of the library on an old Fedora machine.
>>
>> When I build a tree, using:
>>
>> g=igraph.Graph.Tree(100,3)
>>
>> and then write the graph to a file (GML format) the result is a
>> directed graph: the GML file reads:
>>
>> Creator "igraph version 0.5 Fri Jun 26 12:31:25 2009"
>> Version 1
>> graph
>> [
>>  directed 1
>> ....
>>
>> Which is not obvious, since the Tree() should default to
>> "type=TREE_UNDIRECTED".
>>
>> Is that a glitch in the old version I am using, or it's a bug?
>> And if it is the latter, has it been fixed in more recent versions?
>> Is there a fix without updating?
>>
>> I guess I should update, but I don't know if the admin will let me :)
>>
>> Thanks,
>>
>> marco
>>
>> --
>> restituiremo il riso ai salici
>>
>>
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>
>
>
> --
> Gabor Csardi <address@hidden>     UNIL DGM
>
>
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Gabor Csardi <address@hidden>     UNIL DGM