Re: [igraph] Understanding the output of stMinCuts

[Gábor Csárdi]

Actually, the graph would do, I don't really need the code that generates it. 

Anyway, it seems that this is a bug in igraph, it does not handle edges with zero weights. A workaround is to replace zero weights with something small:

E(g)$weight <- ifelse(E(g)$weight == 0, 1e-10, E(g)$weight)

and the output seems to make more sense. I created a bug report for this:

https://github.com/igraph/igraph/issues/628

Gabor

On Tue, Jun 3, 2014 at 10:31 PM, Tom Wright <address@hidden> wrote:

Hi Gábor,

Thank you for taking a look at this.
I've posted an example: http://pastebin.com/aUi9vkyk

On Tue, 2014-06-03 at 21:58 +0200, Gábor Csárdi wrote:
> Please provide a reproducible example.
> See http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example
>
>
> Thanks, Gabor
>
>
> On Tue, Jun 3, 2014 at 7:02 PM, Tom Wright <address@hidden> wrote:
>         Hi,
>         This is probably a gap in my knowledge but can someone please
>         help me
>         understand the output I am getting from the stMincuts
>         function?
>
>         With the example attached I don't understand why cut$cuts[[1]]
>         is empty.
>
>         The graph I am using is pictured in the attachment, all edges
>         to
>         vertices s & t have value 1, all other edges have value 1000.
>
>         Thanks,
>         Tom
>
>         > cut<-stMincuts(g,'s','t')
>         > cut
>         $value
>         [1] 5
>
>         $cuts
>         $cuts[[1]]
>         numeric(0)
>
>         $cuts[[2]]
>          [1]  89  90  91  92  93  94  95  96  97  98  99 100 101 102
>         103
>
>
>         $partition1s
>         $partition1s[[1]]
>         [1] 30 24 18 12  6
>
>         $partition1s[[2]]
>          [1] 30 24 18 12  6 31 29 28 27 26 25 23 22 21 20 19 17 16 15
>         14 13 11
>         10  9  8  7  5  4  3  2  1
>
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