dplyr - using mutate() like rowmeans()

Question

I can\'t find the answer anywhere.

I would like to calculate new variable of data frame which is based on mean of rows.

For example:

data &l         


        

Answer 1

I think the answer suggesting using data.frame or slicing on . is the best, but could be made simpler and more dplyr-ish like so:

data %>% mutate(c = rowMeans(select(., a,b)))

Or if you want to avoid ., with the penalty of having two inputs to your pipeline:

data %>% mutate(c = rowMeans(select(data, a,b)))