Works alright for me: > summarise(baseball,duration = max(year) - min(year),nteams = > length(unique(team))) duration nteams 1 136 132
> ddply(baseball, "id", summarise, duration = max(year) - min(year), nteams > = length(unique(team))) id duration nteams 1 aaronha01 22 3 2 abernte02 17 7 3 adairje01 12 4 4 adamsba01 20 2 5 adamsbo03 13 4 .... .... cheers, -Girish > sessionInfo() 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] grid stats graphics grDevices utils datasets methods base other attached packages: [1] RWinEdt_1.8-1 gtools_2.6.1 gmodels_2.15.0 ggplot2_0.8.3 reshape_0.8.3 [6] plyr_0.1.9 proto_0.3-8 doBy_4.0.2 loaded via a namespace (and not attached): [1] cluster_1.12.0 Formula_0.1-3 gdata_2.6.1 Hmisc_3.7-0 kinship_1.1.0-23 [6] lattice_0.17-25 MASS_7.2-48 nlme_3.1-94 plm_1.1-4 sandwich_2.2-1 [11] splines_2.9.2 survival_2.35-7 tools_2.9.2 ------------------------------------------------------------- Veerappa Chetty wrote: > > Hi,I am using the amazing package 'plyr". I have one problem. I would > appreciate help to fix the following error: Thanks. > ______________________________ > >> library(plyr) >> data(baseball) >> summarise(baseball, > + duration = max(year) - min(year), > + nteams = length(unique(team))) > Error: could not find function "summarise" >> ddply(baseball, "id", summarise, > + duration = max(year) - min(year), > + nteams = length(unique(team))) > Error in llply(.data = .data, .fun = .fun, ..., .progress = .progress) : > object "summarise" not found > -------------------------------------------- > > -- > Professor of Family Medicine > Boston University > Tel: 617-414-6221, Fax:617-414-3345 > emails: chett...@gmail.com,vche...@bu.edu > > [[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. > > -- View this message in context: http://www.nabble.com/summarize-plyr-package-tp25612974p25613167.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.