I suspect reshape() is the function you're looking for; there is also a reshape package that you might prefer.
It's also quite easy to do this in base R using unlist() and some indexing with rep, but that may be more than you care to deal with. Bert Gunter Genentech Nonclinical Biostatisics -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Richardson, Patrick Sent: Thursday, August 27, 2009 4:37 PM To: r help Subject: [R] Transform data for repeated measures I have a dataset that I'm trying to rearrange for a repeated measures analysis: It looks like: patient basefev1 fev11h fev12h fev13h fev14h fev15h fev16h fev17h fev18h drug 201 2.46 2.68 2.76 2.50 2.30 2.14 2.40 2.33 2.20 a 202 3.50 3.95 3.65 2.93 2.53 3.04 3.37 3.14 2.62 a 203 1.96 2.28 2.34 2.29 2.43 2.06 2.18 2.28 2.29 a 204 3.44 4.08 3.87 3.79 3.30 3.80 3.24 2.98 2.91 a And I want to make it look like: Patient FEV time drug 201 2.46 0 a 201 2.68 1 a 201 2.76 2 a 201 2.50 3 a And so on . . . . . There would be 9 "time" and drug is a factor variable. I know there is a way to do this in R but I cannot remember the function. I've looked at the transpose function in (base) but that doesn't seem to be what I want. Can something like this be done easily from within package functions or would it require writing something custom? Another program would use something like the transpose procedure, but I'm trying to stay away from that program. Thanks, Patrick R version 2.9.2 (2009-08-24) i386-pc-mingw32 locale: LC_COLLATE=English_United States.1252;LC_CTYPE=English_United States.1252;LC_MONETARY=English_United States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252 attached base packages: [1] grDevices datasets tcltk splines graphics stats utils methods base other attached packages: [1] svSocket_0.9-43 svMisc_0.9.48 TinnR_1.0.3 R2HTML_1.59-1 Hmisc_3.6-1 survival_2.35-4 loaded via a namespace (and not attached): [1] cluster_1.12.0 grid_2.9.2 lattice_0.17-25 tools_2.9.2 This email message, including any attachments, is for th...{{dropped:8}} ______________________________________________ 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.
