Dear Robin, It is rather easy if you combine melt() and cast() from the reshape package.
dataset <- expand.grid(year = 1940:1942, cell = 1:2) dataset$Q1 <- rnorm(nrow(dataset)) dataset$Q2 <- rnorm(nrow(dataset)) dataset$Q3 <- rnorm(nrow(dataset)) dataset$Q4 <- rnorm(nrow(dataset)) library(reshape) datasetMelt <- melt(dataset, id.var = c("year", "cell")) cast(datasetMelt, year + variable ~ ...) HTH, Thierry ------------------------------------------------------------------------ ---- ir. Thierry Onkelinx Instituut voor natuur- en bosonderzoek / Research Institute for Nature and Forest Cel biometrie, methodologie en kwaliteitszorg / Section biometrics, methodology and quality assurance Gaverstraat 4 9500 Geraardsbergen Belgium tel. + 32 54/436 185 thierry.onkel...@inbo.be www.inbo.be To call in the statistician after the experiment is done may be no more than asking him to perform a post-mortem examination: he may be able to say what the experiment died of. ~ Sir Ronald Aylmer Fisher The plural of anecdote is not data. ~ Roger Brinner The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from a given body of data. ~ John Tukey -----Oorspronkelijk bericht----- Van: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] Namens Robin Hankin Verzonden: donderdag 22 januari 2009 10:52 Aan: r-help@r-project.org Onderwerp: [R] reshape() problems Hi I have a data frame with timeseries information like this: year cell Q1 Q2 Q3 Q4 1940 1 1.2 1.4 1.4 1.9 1941 1 2.9 2.1 3.4 2.4 1942 1 2.7 3.2 1.5 2.6 1940 2 1.4 2.1 2.6 2.4 1941 2 2.4 1.4 1.4 3.4 1942 2 1.4 2.4 2.5 4.4 where the Qs mean 'quarter'. I want to extract from this a dataframe with a timeseries for each cell: year quarter cell1 cell2 1940 1 1.2 1.4 1940 2 1.4 2.1 1940 3 1.4 2.6 1940 4 1.9 2.4 1941 1 2.9 2.4 1941 2 2.1 1.4 1941 3 3.4 1.4 1942 4 2.4 3.4 1942 1 2.7 1.4 1942 2 3.2 2.4 1942 3 1.5 2.5 1942 4 2.6 4.4 Thus the third and fourth columns are the timeserieses for cell 1 and cell 2. Is there a nice vectorized way to do this? I can't quite make reshape() do what I want. [the real dataset is months, not quarters, has ~2000 cells and ~60 years] -- Robin K. S. Hankin Uncertainty Analyst University of Cambridge 19 Silver Street Cambridge CB3 9EP 01223-764877 ______________________________________________ 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. Dit bericht en eventuele bijlagen geven enkel de visie van de schrijver weer en binden het INBO onder geen enkel beding, zolang dit bericht niet bevestigd is door een geldig ondertekend document. The views expressed in this message and any annex are purely those of the writer and may not be regarded as stating an official position of INBO, as long as the message is not confirmed by a duly signed document. ______________________________________________ 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.