Two questions: 1. How do I replace "NA" with 0? 2. How can I sort the observations by their id instead of by time? (actually i can see what you produced is automatically sorted by id; but in my case, the output data is sorted by time)
On 1/27/07, Chuck Cleland <[EMAIL PROTECTED]> wrote: > > gallon li wrote: > > i have a large longitudinal data set. The number of observations for > each > > subject is not the same across the sample. The largest number of a > subject > > is 5 and the smallest number is 1. > > > > now i want to make each subject to have the same number of observations > by > > filling zero, e.g., my original sample is > > > > id x > > 001 10 > > 001 30 > > 001 20 > > 002 10 > > 002 20 > > 002 40 > > 002 80 > > 002 70 > > 003 20 > > 003 40 > > 004 ...... > > > > now i wish to make the data like > > > > id x > > 001 10 > > 001 30 > > 001 20 > > 001 0 > > 001 0 > > 002 10 > > 002 20 > > 002 40 > > 002 80 > > 002 70 > > 003 20 > > 003 40 > > 003 0 > > 003 0 > > 003 0 > > 004 ...... > > > > so that each id has exactly 5 observations. is there a function which > can > > allow me do this quickly? > > Filling in with zeros seems like a bad idea, but here is an approach > to filling in with NAs. I will leave replacing the NAs with zeros to you. > > df.long <- data.frame(id = c(1,1,1,2,2,2,2,2,3,3), x = runif(10), > time = c(1,2,5,1,2,3,4,5,2,4)) > > df.long > id x time > 1 1 0.72888215 1 > 2 1 0.60893548 2 > 3 1 0.41347690 5 > 4 2 0.79388248 1 > 5 2 0.05810054 2 > 6 2 0.02451654 3 > 7 2 0.85464775 4 > 8 2 0.15970365 5 > 9 3 0.22856183 2 > 10 3 0.38291471 4 > > df.wide <- reshape(df, idvar = "id", v.names = "x", direction="wide") > > df.wide > id x.1 x.2 x.5 x.3 x.4 > 1 1 0.6375135 0.1651258 0.3210223 NA NA > 4 2 0.9878134 0.8909020 0.9853269 0.7747615 0.3834130 > 9 3 NA 0.3586109 NA NA 0.8310539 > > df.long2 <- reshape(df.wide, direction="long") > > df.long2 > id time x > 1.1 1 1 0.6375135 > 2.1 2 1 0.9878134 > 3.1 3 1 NA > 1.2 1 2 0.1651258 > 2.2 2 2 0.8909020 > 3.2 3 2 0.3586109 > 1.5 1 5 0.3210223 > 2.5 2 5 0.9853269 > 3.5 3 5 NA > 1.3 1 3 NA > 2.3 2 3 0.7747615 > 3.3 3 3 NA > 1.4 1 4 NA > 2.4 2 4 0.3834130 > 3.4 3 4 0.8310539 > > This assumes that your data in the "long" format has a time variable. > See the help page for reshape() for more details. > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > [email protected] 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. > > -- > Chuck Cleland, Ph.D. > NDRI, Inc. > 71 West 23rd Street, 8th floor > New York, NY 10010 > tel: (212) 845-4495 (Tu, Th) > tel: (732) 512-0171 (M, W, F) > fax: (917) 438-0894 > [[alternative HTML version deleted]] ______________________________________________ [email protected] 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.
