Re: [igraph] Question about ploting graph in animation

[Gábor Csárdi]

Hello,

layout.fruchterman.reingold() calculates the layout from a random
initial configuration by default, so you get different layouts each
time you call it. Calculate the layout before the loop and use the
same configuration for all plots:

coords <- layout.fruchterman.reingold(g1)
for (...) {
   ...
   plot(g1, layout=coords, ...)
   ...
}

Gabor

On Wed, Apr 21, 2010 at 6:09 PM, Zhu, Hong <address@hidden> wrote:
> Hello  igraph users,
>
> I am trying to create animation and plot the network after each iteration. It 
> does show the animation and change of the network.
> But the problem is the graph does not have a fixed orientation, while on the 
> contrast, the nodes move around over time with the
> iterations.
>
> I wonder whether there is something wrong with "layout" option. Because if we 
> use "circle" or "tree" layout, the nodes are fixed but
> it is not the graphical presentation we want.
>
> Any comments to help? Thanks a lot in advance!
>
> Best,
>
> Hong
>
> The following is the code.
>
> #
> mrule <- function(A, y) {
> # Majority rule dynamics
> # A = adjacency matrix
> # y = state of the vertices at time t
> #
>        apply(cbind(A, y), 1, z=y, function(x, z){
>        n <- length(x)
>        if (sum(x[-n]) == 0) return(x[n])
>        z <- z[x[-n]==1]
>        zf <- factor(z, levels=c(0,1))
>        cz <- table(zf)
>        if (cz[1] != cz[2]) c(0,1)[which.max(cz)] else rbinom(n=1, size=1, 
> prob=0.5)
>        })
> }
>
>
> ## nt is step, try nt=(25, 50, 100)
> nt <- 50
> ani.options(interval = 0.5, nmax = nt ,title="Animation for mrule")
> ani.start()
> par(mar=c(3,2.5,1,0.2),pch=20,mgp=c(1.5,0.5,0))
> interval = ani.options("interval")
>
> g1<-ba.game(100,m=2,directed=F)
> g1<-add.edges(g1,c(97,98,98,99))
> nv<-vcount(g1)
> ne<-ecount(g1)
> ##Assign original status
> y0<-V(g1)$status<-rbinom(nv, size=1, prob=0.5) # state of the nodes at time 
> #= 0
> V(g1)$color<-ifelse(V(g1)$status==0,"red","blue")
>
> A <- get.adjacency(g1,binary=TRUE)
> y_m<-y_p <- y0
> s1_m <- rep(NA, nt)
> s1_m[1] <- sum(y_m)
> plot(g1,layout=layout.fruchterman.reingold, 
> vertex.size=4,vertex.label=NA,edge.arrow.size=0.5)
>
> for (i in 2:nt) {
>        y_m <- mrule(A, y=y_m) # State at time = i - 1
>        V(g1)$color<-ifelse(y_m==0,"red","blue")
>
> plot(g1,layout=layout.fruchterman.reingold,vertex.size=4,vertex.label=NA,edge.arrow.size=0.5)
> Sys.sleep(interval)
> #dev.off()
> }
>
> _______________________________
> Hong Zhu
> Ph.D. Candidate, Biostatistics
> Bloomberg School of Public Health
> Johns Hopkins University
>
> _______________________________________________
> igraph-help mailing list
> address@hidden
> http://lists.nongnu.org/mailman/listinfo/igraph-help
>



-- 
Gabor Csardi <address@hidden>     UNIL DGM