Hello, rollapply in zoo can probably help you :
> x <- zoo( 1:10 ) > rollapply( x, 4, sum ) 2 3 4 5 6 7 8 10 14 18 22 26 30 34 > sum( x[1:4] ) [1] 10 > sum( x[2:5] ) [1] 14 Cheers, Romain -- Mango Solutions data analysis that delivers Introduction to R training course :: London :: 06-07 March 2008 http://www.mango-solutions.com/services/rtraining/r_intro.html joshv wrote: > Hello, I'm new to R and would like to know how to create a vector of "rolling > sums". (I have seen the Rmetrics package and the rollMean function and I > would like to do the same thing except Sum instead of Mean.) I imagine > someone has done this, I just can't find it anywhere. > > Example: > x <- somevector #where x is 'n' entries long > > #what I would like to do is: > > x1 <- x[1:20] > output1 <- sum(x1) > > x2 <- x[2:21] > output2 <- sum(x2) > > x3 <- ... > > ouput <- c(output1, output2, ...) > > > Thanks, > JV > ______________________________________________ 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.
