Hi, Try opening and closing the device outside the loop,
pdf("D:/research/plot.pdf") for (i in 1:n) { plot(mon, mu, type ='o') } dev.off() HTH, baptiste ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.