Re: [igraph] adding a new edge attribute with 1 or more zero values deletes all edges

[Gábor Csárdi]

On Wed, Oct 31, 2012 at 12:47 PM, Gábor Csárdi <address@hidden> wrote:
> On Wed, Oct 31, 2012 at 12:32 PM, Tony Larson <address@hidden> wrote:
>> Thanks Gabor,
>> That's helpful.
>>
>> However, another problem I've run across is setting edge attributes.  If I
>> add a new numeric edge attribute with a value of  0 for ANY edge (or all,
>> edges but a single 0 is enough), ALL edges are deleted!
>
> Probably this is a bug, I'll investigate it.

I actually cannot reproduce this. The following all works fine:

library(igraph)

g <- graph.ring(10)
g[1,2,attr="weight"] <- 0
g

el <- get.edgelist(g)
g[from=el[,1], to=el[,2], attr="sim"] <- seq_len(ecount(g))
g

V(g)$name <- letters[seq_len(vcount(g))]
el <- get.edgelist(g)
g[from=el[,1], to=el[,2], attr="sim"] <- seq_len(ecount(g))
g

So I'll need some information on what exactly you did, including toy
data that shows the problem.

Best,
Gabor

[...]