New matrix containing difference between row elements of original

Question

I want to take an existing MxN matrix and create a new M-1xN matrix such that for each columns, the elements are the difference between adjacent row elements of the original

Answer 1

It's very simple for numerical data (not sure why you have characters):

diff(m)

With the character data, this should work:

diff(matrix(as.numeric(m), dim(m)))