[igraph] Change order of vertices in an igraph object

[Hermann Norpois]

Hello,

having an igraph object sig (see below) I am looking for a way to change the order of vertices in reference to x.
So I guess I have something to use like
idx -> order (V(sig)$x)
to get a new index. But how do I insert this index in the igraph object to get a newly ordered igraph object?

Thanks Hermann

> dput (sig)
structure(list(13, TRUE, c(0, 0, 1, 6, 6, 6, 7, 7, 8, 9, 11),
    c(1, 3, 3, 7, 11, 12, 11, 12, 9, 10, 12), c(0, 1, 2, 3, 4,
    5, 6, 7, 8, 9, 10), c(0, 1, 2, 3, 8, 9, 4, 6, 5, 7, 10),
    c(0, 2, 3, 3, 3, 3, 3, 6, 8, 9, 10, 10, 11, 11), c(0, 0,
    1, 1, 3, 3, 3, 3, 4, 4, 5, 6, 8, 11), list(c(1, 0, 1), structure(list(), .Names = character(0)),
        structure(list(name = c("rs5761629", "rs12628704", "rs2267104",
        "rs5761630", "rs5761631", "rs4822752", "rs58450956",
        "rs16982453", "rs5761635", "rs2283843", "rs5997109",
        "rs16982454", "rs76095025"), x = c(27005470L, 27006136L,
        27006308L, 27006698L, 27007269L, 27011420L, 27014346L,
        27014428L, 27014467L, 27017300L, 27017435L, 27017996L,
        27018001L), y = c(0.887869230924378, 0.654212551439585,
        0.755969155644639, 0.895054710863134, 0.591152110066053,
        0.841717655905212, 1, 1, 0.79443719113136, 0.794554251603377,
        0.435233706137542, 1, 1)), .Names = c("name", "x", "y"
        )), structure(list(weight = c(0.920156, 0.986379, 0.905977,
        1, 1, 1, 1, 1, 0.944149, 0.822451, 1)), .Names = "weight"))), class = "igraph")
>