Done: https://github.com/igraph/igraph/issues/865
Note that I've tried again on Linux (the first try was on Windows), and for some reason it seems to work (with the same igraph version).
Cheers,
Vincent
> Ah, my bad, I did not notice that you meant the edge betweenness and
> not the node betweenness. It looks like the edge betweenness related
> code does not include a similar bigint workaround. This should be
> fixed in the next version then - can you add a bug report to
> https://github.com/igraph/igraph/issues ?
>
> Thanks,
> T.
>
>> On Sun, Sep 13, 2015 at 9:24 AM, Vincent Labatut <address@hidden> wrote:
>> Hello Tamas,
>>
>> and thanks for your answer.
>> I was thinking of something like that, since the networks are lattices and
>> this case is mentionned in the documentation.
>> I also had noticed the "nobigint" parameter for the "betweenness" functions,
>> however it does not exist for the "edge.betweenness" functions.
>> Best,
>> Vincent
>>
>>> Hello,
>>>
>>> The negative values are most likely due to integer overflows (i.e. the
>>> betweenness score would be too large and the underlying variable in
>>> which igraph computes the betweenness score overflows). You can get
>>> around this by passing nobigint=FALSE to the edge betweenness call -
>>> it will make igraph use "big integers", which can hold arbitrarily
>>> large numbers at the expense of being somewhat slower.
>>>
>>> As for the NaNs, it could be a bug, but let's see first whether the
>>> issue persists with nobigint=FALSE. If so, let us know and try to post
>>> a small example on which we could reproduce the issue with NaNs.
>>>
>>> T.
>>>
>>>
>>>
>>> On Sat, Sep 12, 2015 at 3:08 PM, Vincent Labatut
>>> <address@hidden> wrote:
>>>> Hello,
>>>>
>>>> I am processing the edge-betweenness of various networks using R igraph
>>>> version 7.1. Those are spatial networks (each node has a (x,y) position)
>>>> and
>>>> I am using the "weight" option of the "edge.betweenness" function to take
>>>> the spatial distances into account. This spatial distance is stored in an
>>>> edge attribute called "dist".
>>>>
>>>> Here is the command I use:
>>>> edge.betweenness(graph=g, weights=E(g)$dist)
>>>>
>>>> However, for some of my networks, I get negative values, or even NaN.
>>>> Here
>>>> are two examples, under the graphml format:
>>>> http://dx.doi.org/10.6084/m9.figshare.1540708
>>>> - scale=32.graphml
>>>> - scale=41.graphml
>>>>
>>>> For the first one, the first values returned by "edge.betweenness" are:
>>>> [1] 1904887544.08 1904887544.08 1896303182.39 1951787568.72
>>>> 1203043060.76
>>>> [6] 1270869072.68 622780616.09 667964773.27 279064394.68
>>>> 309184936.21
>>>> [11] 135403467.81 155266075.94 51600202.02 60120695.31
>>>> 21113003.39
>>>> [16] 24783603.89 6275147.30 6937885.52 1347425.01
>>>> 1002544.99
>>>> [21] 150574.42 -327097.77 -711849.38 -1430744.36
>>>> -246214.20
>>>> [26] -602827.15 -230344.97 -484630.12 -297768.08
>>>> -492364.06
>>>>
>>>> For the second one, all the returned values are NaN.
>>>>
>>>> Note that all these weights are positive by definition. They even are
>>>> non-zero since no two nodes hold the same position, by construction. I
>>>> also
>>>> checked this programmatically. Moreover, there are no multiple links,
>>>> also
>>>> by construction (and I checked with "has.multiple").
>>>>
>>>> I was wondering if the negative or NaN values I get are due to me
>>>> misusing
>>>> the function, or if this is a bug in igraph.
>>>>
>>>> Thanks,
>>>> Vincent Labatut
>>>>
>>>> _______________________________________________
>>>> igraph-help mailing list
>>>> address@hidden
>>>> https://lists.nongnu.org/mailman/listinfo/igraph-help
>>>>