On Aug 23, 2013, at 9:41 AM, Anindya Sankar Dey wrote: > You can easily subset the data then use rowSum. > > say your dataset name is data1. > > then write data2<-data[,c(7,12,45,57)] > > then write result<-rowsum(data2)
In R there are two different functions `rowsum` and `rowSums`. The use you are describing sounds like a case rowSums, rather than `rowsum`. For reasons that are unclear to me `rowsum` seems to be more like `grouped.colSums` than anything I would have imagined it to be just looking at its name and then looking at its help page. I think you wanted: dfrm$m <- rowSums( dfrm[, c(7,12,57,45) ] ) # assuming dfrm is a dataframe. -- David. > > > On Fri, Aug 23, 2013 at 3:47 PM, rajib prasad <rwho2...@gmail.com> wrote: > >> I am new to R. I have a data like: >> >> x y z w p .......... >> m >> 1 10 15 20 25 30 >> 2 11 16 21 26 31 >> 3 12 17 18 19 20 >> 4 51 52 53 55 67 >> ....... >> >> thus I have 145 rows and 160 column in my data which is named as >> data.csv. Now i want to create a new column 'm' and for every row m >> will take value =column 7+ column 12+ column 57+ column 45 i.e. for >> every row it will take value of sum of corresponding row's 7 & 12 & 57 >> & 45 column's value . >> So, how to write the code for this operation? >> David Winsemius Alameda, CA, USA ______________________________________________ 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.
