Hi, thanks for your quick answers! These solve my problem.
Now I have another question. I think I can use head(y, -1) instead of y[-length(y)] Are there differences in terms of performance? Best regards Joseph ______________________________________________ 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.
