Have a look at cast() from the reshape package. library(reshape) cast(personId ~ law, data = testdata, value = "article", fun = length) cast(personId ~ law, data = testdata, value = "article", fun = function(x){1 * (length(x) > 0)})
________________________________________ Van: r-help-boun...@r-project.org [r-help-boun...@r-project.org] namens David Studer [stude...@gmail.com] Verzonden: maandag 4 maart 2013 16:44 Aan: r-help@r-project.org Onderwerp: [R] urgent: question concerning data manipulation Hello everyone! Does anyone of you know how I could solve the following problem. I guess, it is not a very difficult question, but I simply lack of the right idea: I have a dataset containing data of convictions. This dataset contains 4 columns: - personId: individual number that identifies the offender - law: law which has been violated - article: article which has been violated # Testdata: personId<-c(1,1,2,2,2,2,2,3,4,4) law<-c("SVG", "SVG", "StGB", "StGB", "SVG", "AuG", "StGB", "SVG", "StGB", "AuG") article<-c(10, 10, 123, 122, 10, 40, 126, 10, 111, 40) testdata<-data.frame(personId, law, article) Now I'd like to create three additional dummy-coded columns for each law (SVG, StGB, AuG). For each offender (all offenders have the same personId) it should be checked, whether there are any violations against the three laws. If there are any violations against SVG (for example), then in all rows of this offender the column SVG should have the value 1 (otherwise 0). For example offender 2 has once violated against law "SVG" therefore his four entries should have the value 1 at the column "SVG". I hope you can understand my problem. I'd really appreciate any hints and solutions! Thank you! David [[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. * * * * * * * * * * * * * D I S C L A I M E R * * * * * * * * * * * * * 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.