Let's say I have some data DIFF, then I do> a <- acf(DIFF, lag.max=2) > a$acf, , 1 [,1] [1,] 1.0000000 [2,] -0.2085724 [3,] -0.1597789> a <- acf(DIFF) > a$acf, , 1 [,1] [1,] 1.00000000 [2,] -0.20857236 [3,] -0.15977892 How come they are different? I thought the max.lag just controls how many lag to compute? -- View this message in context: http://www.nabble.com/How-does-max.lag-work--tf3607611.html#a10079456 Sent from the R help mailing list archive at Nabble.com.