[igraph] Odd error message

Hello again

When I run the following code

<<<<

DVg <- graph.empty()

DVg <- add.vertices(DVg, nrow(DVtraits),

ISBN=as.character(DVtraits[,1]),

title=as.character(DVtraits[,2]), author = as.character(DVtraits[,3]),

publisher = as.character(DVtraits[,4]), salesrank = as.character(DVtraits[,6]),

category = as.character(DVtraits[,5]))

names <- V(DVg)$ISBN

ids <- 1:length(names)-1

names(ids) <- names

from <- as.character(DVlinks[,1])

to <- as.character(DVlinks[,2])

edges <- matrix(c(ids[from], ids[to]), nc=2)

DVg <- add.edges(DVg, t(edges))

>>>>

I get (after running the last line) an error:

Traceback:

1: .Call("R_igraph_add_edges", graph, as.numeric(edges), PACKAGE = "igraph")

2: add.edges(DVg, t(edges))

Error in add.edges(DVg, t(edges)) :

caught access violation - continue with care

Last time this happened, it turned out to be that there were some NA in the from and to, but there are not this time.

I am not sure how to create a toy example…. Or what else would be helpful here.

Thanks (and if someone wants me to send the data, I can send it)

Peter

Peter Flom

Peter Flom Consulting