Your variable mat is not a matrix; its a data frame. Check it with: class(mat)
Here is an example: x <- cbind(A = 1:4, B = 5:8) tt <- c(1, 3:4, 6) library(zoo) x.zoo <- zoo(x, tt) x.ts <- as.ts(x.zoo) On 12/13/05, Alvaro Saurin <[EMAIL PROTECTED]> wrote: > > Hi, > > First, thank you. It 'almost' works: I can convert a matrix to a > 'zoo' object, but it can not convert it to a 'ts'. > > The sitruation is this: I load a set of samples with > > > h_types <- list (0, 0, character(0), character(0), 0, 0, 0, 0, 0) > > h_names <- list ("time", "flow", "type", "dir", "seq", "ts", "x", > "rtt", "size") > > pcks_file <- pipe ("grep ' P ' server.dat"), "r") > > pcks <- scan (pcks_file, what = h_types, comment.char = > '#', > fill = TRUE) > Read 1429 records > > > mat <- data.frame (pcks) > > colnames (mat) <- h_names > > mat > > time flow type dir seq ts x rtt size > 1 1.000893 0 P + 0 1.000893 1472 0.000000 1472 > 2 1.514454 0 P + 1 1.514454 2944 0.513142 1472 > 3 2.015093 0 P + 2 2.015093 2944 0.513142 1472 > 4 2.515025 0 P + 3 2.515025 4806 0.504488 1472 > 5 2.821976 0 P + 4 2.821976 5730 0.496728 1472 > 6 3.078931 0 P + 5 3.078931 5832 0.489744 1472 > 7 3.331897 0 P + 6 3.331897 5832 0.489744 1472 > > [...] > > 1425 176.925504 0 P + 1424 176.925504 12141 0.764699 1472 > 1426 177.039489 0 P + 1425 177.039489 12141 0.764699 1472 > 1427 177.153469 0 P + 1426 177.153469 12141 0.764699 1472 > 1428 177.267464 0 P + 1427 177.267464 12141 0.764699 1472 > 1429 177.381434 0 P + 1428 177.381434 12141 0.764699 1472 > > Then I convert it to a 'zoo', removing the 'time' column from the input > > > last_col <- ncol (mat) > > range_cols <- 2:last_col > > matrix_values <- mat [,range_cols] > > z <- zoo (matrix_values, mat $ time) > > So far, everything is fine. But then I need to apply a function to > samples taken every t seconds, ie, the mean every 10 seconds. And, > AFAIK, rapply needs a constant 'width', something that can only be > obtained with regular time series... But if I try to get a 'ts' > object from my 'zoo' I get > > > as.ts (z) > Error in if (del == 0 && to == 0) return(to) : > missing value where TRUE/FALSE needed > > Ummm, do you know if there is any error in my 'zoo' object? Has it > the right format? Or, could I avoid the conversion and use the > 'rapply' function but on time intervals (instead of points intervals)? > > Thank you very much. > > Alvaro > > > On 12 Dec 2005, at 16:31, Gabor Grothendieck wrote: > > > First we generate some sample data x and its times tt. > > Then using the zoo package we create an irregularly > > spaced time series. Now if you want a regularly spaced > > time series convert it to ts class. After loading zoo as > > shown below, the R command vignette("zoo") gives more info. > > > > x <- 1:4 > > tt <- c(1, 3, 4, 6) > > > > library(zoo) > > x.zoo <- zoo(x, tt) # irregularly spaced time series > > x.ts <- as.ts(x.zoo) # regular time series with NAs > > > > > > On 12/12/05, Alvaro Saurin <[EMAIL PROTECTED]> wrote: > >> > >> Hi, > >> > >> I am a R begginer and I have a small problem with time series. I was > >> wondering if someone could help me > >> > >> I am collecting data from packets going through a network, and using > >> R for obtaining some simple statistics of connections. However, my > >> data is not collected at a constant frequency, so I would like to > >> create a evenly spaced TS from my traces, using the minimum time > >> difference between two samples as the period for my new TS, and > >> filling the gaps with NA (or 0s). > >> > >> I think ther must be some simple solution for this... Anyone could > >> help me? > >> > >> Thanks in advance. > >> > >> -- > >> Alvaro Saurin <[EMAIL PROTECTED]> <[EMAIL PROTECTED]> > >> > >> ______________________________________________ > >> R-help@stat.math.ethz.ch mailing list > >> https://stat.ethz.ch/mailman/listinfo/r-help > >> PLEASE do read the posting guide! http://www.R-project.org/posting- > >> guide.html > >> > > -- > Alvaro Saurin <[EMAIL PROTECTED]> <[EMAIL PROTECTED]> > > > > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html