Is exp3 <- c(rep(NA, 3), seq_along(x)) what you are looking for? > x[exp3][10] [1] "g"
(I presume you meant x <- letters[1:10]: R is case-sensitive and you don't need c() to concatenate a single vector.) On Wed, 2 Jan 2008, Antonio Gasparrini wrote: > Dear all, > > I would like to know if it's possible to create an index for a > variable/vector that specifies the value in the n position before the > actual value. > > For example, if X <- c(letters[1:10]), x[10] is 'j'. I would like to > create an index exp3 (the third position before) such as if z <- > x[exp3], then z[10] = 'g'. > > In Stata that index is x[-3], but not in R. > > I have to input it in a very complex function to be minimised with the > mle command, so I can't solve this problem with a loop. > > Can you help me? -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ 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.
