order order returns the position of each element of a vector in ascending (or descending order). Examples Given a matrix, arrange it in ascending order using the first column. Click to see solution my_mat <- matrix(c(1,5,0, 2, 10, 1, 2, 8, 9, 1,0,2), ncol=3) my_mat[order(my_mat[,1]),] [,1] [,2] [,3] [1,] 0 2 0 [2,] 1 10 9 [3,] 2 8 2 [4,] 5 1 1 sort length