How to get rowSums for selected columns in R

Question

I am a newbie to R and seek help to calculate sums of selected column for each row. My simple data frame is as below.

data = data.frame(location = c(\"a\",\"b\"         


        

Answer 1

Specifying the two summations explicitly:

cbind(x1=rowSums(data[,c('v1','v2','v3')]),x2=rowSums(data[,c('v4','v5','v6')]));
##       x1 x2
## [1,]  14 13
## [2,]  66 18
## [3,]   8 12
## [4,] 100 24