Hi Everyone, I have a question about for loops. If you have something like:
f <- function(x) { y <- rep(NA,10); for( i in 1:10 ) { if ( i > 3 ) { if ( is.na(y[i-3]) == FALSE ) { # some calculation F which depends on one or more of the previously generated values in the series y[i] = y[i-1]+x[i]; } else { y[i] <- x[i]; } } } y } e.g. > f(c(1,2,3,4,5,6,7,8,9,10,11,12)); [1] NA NA NA 4 5 6 13 21 30 40 is there a faster way to process this than with a 'for' loop? I have looked at lapply as well but I have read that lapply is no faster than a for loop and for my particular application it is easier to use a for loop. Also I have seen 'rle' which I think may help me but am not sure as I have only just come across it, any ideas? Many thanks Tom -- Dr. Thomas McCallum Systems Architect, Level E Limited ETTC, The King's Buildings Mayfield Road, Edinburgh EH9 3JL, UK Work +44 (0) 131 472 4813 Fax: +44 (0) 131 472 4719 http://www.levelelimited.com Email: [EMAIL PROTECTED] Level E is a limited company incorporated in Scotland. The c...{{dropped}} ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel