> mx <- matrix(c(1, 2, 3, 4, 5, 6, 7, 8, 8), 3, 3) > mxlu <- expand(lu(mx)) > mxlu$L 3 x 3 Matrix of class "dtrMatrix" (unitriangular) [,1] [,2] [,3] [1,] 1.0000000 . . [2,] 0.3333333 1.0000000 . [3,] 0.6666667 0.5000000 1.0000000 > mxlu$U 3 x 3 Matrix of class "dtrMatrix" [,1] [,2] [,3] [1,] 3.000000 6.000000 8.000000 [2,] . 2.000000 4.333333 [3,] . . 0.500000