[igraph] combine 2 plots - one network and one phylogenetic tree with R

[Augusto Ribas]

Hello.
I was using the package ipgraph to plot networks of parasites 
and hosts in R. Then i though about plug a phylogeny tree on the plot. But 
I'm having some difficulties to do so.

#I have data that look like this, 6 parasites ("P") and six host species ("P")
dados<-matrix(c(1,1,1,1,0,0,
                0,1,1,1,0,0,
                0,0,1,1,0,0,
                0,0,0,0,1,0,
                0,0,0,0,0,1,
                0,0,0,0,0,1),byrow=T,ncol=6,

nrow=6,
                dimnames=list(paste("P",1:6,sep=""),paste("H",1:6,sep="")))
dados

#Then i convert the data a way i can use with igraph packages
#Is there a more elegant way to change data like this anyway?

library(igraph)
dados.network<-cbind(expand.grid(rownames(dados),colnames(dados)),Presence=c(dados[,]))
dados.network<-dados.network[which(dados.network$Presence==1),1:2]
dados.igraph<-graph.data.frame(dados.network)

#now i would like to combine 2 plots,
#one phylogenetic tree of the hosts:

library(ape)
host.tree<-rtree(6,rooted=

TRUE,tip.label=paste("H",1:6,sep=""))

#with the network, but the network would have to had  a layout like in package bipartite
library(bipartite)

#Take the order of the hosts from the tree
order<-host.tree$tip.lab

par(mfrow=c(2,1))

#remove the host names from the tree to not repeat the network
plot(host.tree,use.edge.

length=F,direction="downwards",show.tip.label =F)

#now plot the network, with the order of the tree
plotweb(dados[,order],method = "normal")

#but i would like to make this:
#something like this draw:
http://oi47.tinypic.com/2j2szcy.jpg

so instead the plotweb for the network plot, i would like to use plot.igraph()
But is there some simple way, like a layout that would make it?
Hope i'm not confuseing everything.