r - Add row to a data frame with total sum for each column

Question

I have a data frame where I would like to add an additional row that totals up the values for each column. For example, Let's say I have this data:

x <- data.frame(Language=c("C++", "Java", "Python"), 
                Files=c(4009, 210, 35), 
                LOC=c(15328,876, 200), 
                stringsAsFactors=FALSE)    

Data looks like this:

  Language Files   LOC
1      C++  4009 15328
2     Java   210   876
3   Python    35   200

My instinct is to do this:

y <- rbind(x, c("Total", colSums(x[,2:3])))

And this works, it computes the totals:

> y
  Language Files   LOC
1      C++  4009 15328
2     Java   210   876
3   Python    35   200
4    Total  4254 16404

The problem is that the Files and LOC columns have all been converted to strings:

> y$LOC
[1] "15328" "876"   "200"   "16404"

I understand that this is happening because I created a vector c("Total", colSums(x[,2:3]) with inputs that are both numbers and strings, and it's converting all the elements to a common type so that all of the vector elements are the same. Then the same thing happens to the Files and LOC columns.

What's a better way to do this?

Answer 1

See adorn_totals() from the janitor package:

library(janitor)
x %>%
  adorn_totals("row")

#>  Language Files   LOC
#>       C++  4009 15328
#>      Java   210   876
#>    Python    35   200
#>     Total  4254 16404

The numeric columns remain of class numeric.

Disclaimer: I created this package, including adorn_totals() which is made for precisely this task.