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

Another simple possibility with few code is:

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

 #     id a b   c
 #  1 101 1 2 1.5
 #  2 102 2 2 2.0
 #  3 103 3 2 2.5

As rowMeans needs something like a matrix or a data.frame, you can use data.frame(var1, var2, ...) instead of c(var1, var2, ...). If you have NAs in your data you'll need to tell R what to do, for example to remove them: rowMeans(data.frame(a,b), na.rm=TRUE)