Change row order in a matrix/dataframe

Question

I need to change/invert rows in my data frame, not transposing the data but moving the bottom row to the top and so on. If the data frame was:

1 2 3 
4 5 6
7         


        

Answer 1

Veeery late, but this seems to be working fast, does not need any extra packages and is simple:

for(i in 1:ncol(matrix)) {matrix[,i] = rev(matrix[,i])}

I guess that for frequent use, one would make a function out of it. Tested with R v=3.3.1.