[R] trellis graphics in loops

[Jean Eid]

I have this awkward problem with trellis (lattice). I am trying to
generate some plots through loops but the .eps file is empty. When I
generate them in a list and print them outside the loop all is fine. this
is an example below:( nothing shows up in foo.eps, but all show up in
foo1.eps)
R vesion 2.0.1, lattice version  0.10-16, on a debian 2.6.8-1 kernel.


X <- data.frame(x=rnorm(10000), y=rnorm(10000), z=sample(c("foo1","foo2"),
10000,replace=T), year=sample(c(89:94), 10000,replace=T))
trellis.device("postscript", file="foo.eps")
for(i in unique(X$year)){
  temp <- X[X$year%in%i, ]
  xyplot(temp$x~temp$y|temp$z)
}
dev.off()

mylist <- list()
for(i in unique(X$year)){
  temp <- X[X$year%in%i, ]
  mylist[[i]] <- xyplot(temp$x~temp$y|temp$z)
}

trellis.device("postscript", file="foo1.eps")
mylist[[89]]
mylist[[90]]
mylist[[91]]
mylist[[92]]
mylist[[93]]
mylist[[94]]
dev.off()


Thank you,

Jean