Hi Guys, I'm using zoo package now. I found lag is not doing what I assumed.
> x <- zoo(11:21) > z <- zoo(1:10, yearqtr(seq(1959.25, 1961.5, by = 0.25)), frequency = 4) > x 1 2 3 4 5 6 7 8 9 10 11 11 12 13 14 15 16 17 18 19 20 21 > lag(x) 1 2 3 4 5 6 7 8 9 10 12 13 14 15 16 17 18 19 20 21 > z 1959 Q2 1959 Q3 1959 Q4 1960 Q1 1960 Q2 1960 Q3 1960 Q4 1961 Q1 1961 Q2 1961 Q3 1 2 3 4 5 6 7 8 9 10 > lag(z) 1959 Q1 1959 Q2 1959 Q3 1959 Q4 1960 Q1 1960 Q2 1960 Q3 1960 Q4 1961 Q1 1961 Q2 1 2 3 4 5 6 7 8 9 10 Why z and lag (z) are of same length while lag(x) is shorter by one than x? I assume lag(z) would give me like this: 1959 Q3 1959 Q4 1960 Q1 1960 Q2 1960 Q3 1960 Q4 1961 Q1 1961 Q2 1961 Q3 2 3 4 5 6 7 8 9 10 ie preserve the relationship between timestamp and the value. Same things applies to lag(x) but I guess both make sense: 1 2 3 4 5 6 7 8 9 10 12 13 14 15 16 17 18 19 20 21 or 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Any insight? Cheers, Bo _________________________________________________________________ [[elided Hotmail spam]] [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.