Basic lag in R vector/dataframe
Will most likely expose that I am new to R, but in SPSS, running lags is very easy. Obviously this is user error, but what I am missing? x <- sample(c(1:9), 10, replace = T) y <- lag(x, 1) ds <- cbind(x, y) ds Results in: x y [1,] 4 4 [2,] 6 6 [3,] 3 3 [4,] 4 4 [5,] 3 3 [6,] 5 5 [7,] 8 8 [8,] 9 9 [9,] 3 3 [10,] 7 7 I figured I would see: x y [1,] 4 [2,] 6 4 [3,] 3 6 [4,] 4 3 [5,] 3 4 [6,] 5 3 [7,] 8 5 [8,] 9 8 [9,] 3 9 [10,] 7 3 Any guidance will be much appreciated. Another way to deal with this is using the zoo package, which has a lag method that will pad the result with NA: require(zoo) >