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## Re: [igraph] connected graph returns shortest.paths with inf

**From**: |
Tamas Nepusz |

**Subject**: |
Re: [igraph] connected graph returns shortest.paths with inf |

**Date**: |
Wed, 1 Sep 2010 10:14:28 +0100 |

**User-agent**: |
Mutt/1.5.20 (2009-06-14) |

Dear Martin,
>* nodes <- V(g);*
>* y<-lapply(nodes,function(x){shortest.paths(g,x)})*
>* *
>* max(y[[1]]) returns Inf, and also sum(y[[1]]==Inf), meaning that*
>* there are disconnected nodes.*
>* *
>* How could that happen?*
First I was thinking that is.connected() in R may be checking for strong
connectedness and your graph may be only weakly connected (meaning that
there is a path from A to B but no path from B to A); however, it turns
out not to be the case (at least not in 0.6). I'm not that familiar with
the R interface, but if you can send me a small(ish) example graph on
which I could reproduce the problem, I'll take a look.
Cheers,
Tamas

**Re: [igraph] connected graph returns shortest.paths with inf**,
*Tamas Nepusz* **<=**