see inline for another vectorized example. On 25 September 2014 23:05, David L Carlson <dcarl...@tamu.edu> wrote: > Another approach > > fun <- function(i, dat=x) { > grp <- rep(1:(nrow(dat)/i), each=i) > aggregate(dat[1:length(grp),]~grp, FUN=sum) > } > > lapply(2:6, fun, dat=TT) > > > ------------------------------------- > David L Carlson > Department of Anthropology > Texas A&M University > College Station, TX 77840-4352 > > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf Of Rui Barradas > Sent: Thursday, September 25, 2014 3:34 PM > To: eliza botto; r-help@r-project.org > Subject: Re: [R] adding rows > > Hello, > > Try the following. > > fun <- function(x, r){ > if(r > 0){ > m <- length(x) %/% r > y <- numeric(m) > for(i in seq_len(m)){ > y[i] <- sum(x[((i - 1)*r + 1):(i*r)]) > } > y > }else{ > NULL > } > }
fun <- function(x,r) { i <- length(x)%/%r tapply(x[1:(i*r)], gl(i,r), sum) } > > apply(TT, 2, fun, r = 2) > apply(TT, 2, fun, r = 3) > etc > > > Hope this helps, > > Rui Barradas > > > Em 25-09-2014 20:50, eliza botto escreveu: >> Dear useRs, >> Here is my data with two columns and 20 rows. >>> dput(TT) >> structure(c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, >> 19, 20, 24, 48, 72, 96, 120, 144, 168, 192, 216, 240, 264, 288, 312, 336, >> 360, 384, 408, 432, 456, 480), .Dim = c(20L, 2L), .Dimnames = list(NULL, >> c("", "SS"))) >> I first of all want to sum up continuously two rows (1 & 2, 3 & 4, 5 & 6 >> and so on) of each column. >> Then I want to sum up 3 rows as (1-2-3,4-5-6,..... 16-17-18) and since 19th >> and 20th rows do not up 3 rows, so they should be ignored. >> Similarly with 4 sets of rows and 5 sets of rows and even 6. >> I hope I was clear. >> Thankyou so very much in advance, >> Eliza >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> 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. >> > > ______________________________________________ > 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. > > ______________________________________________ > 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. ______________________________________________ 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.