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

We can split the dataset into a list and then use Reduce with f="+".

sapply(split.default(data[-1], rep(paste0("x", 1:2), each=3)), Reduce, f=`+`)
#     x1 x2
#[1,]  14 13
#[2,]  66 18
#[3,]   8 12
#[4,] 100 24