Dear Matt, yes you have. 'plm' doesn't support multi-column time indices, but it should happily make do with any *single* time index whose order can be recognized by R, such as, e.g., a lexicographic ordering. So you will probably want to paste your indices along these lines:
> year <- rep(2000:2001,times=c(4,4)) > year [1] 2000 2000 2000 2000 2001 2001 2001 2001 > > quarter <- rep(1:4,times=2) > quarter [1] 1 2 3 4 1 2 3 4 > > myind <- paste(year, quarter, sep="q") > myind [1] "2000q1" "2000q2" "2000q3" "2000q4" "2001q1" "2001q2" "2001q3" "2001q4" > > order(myind) [1] 1 2 3 4 5 6 7 8 (of course you must be careful with the double digits in case of months and so on). As all 'plm' uses is "standard" R ordering, please refer to the general documentation of the R system for any issues. Best wishes, Giovanni ------------- original message ----------------- Message: 182 Date: Wed, 3 Feb 2010 10:37:13 +0100 From: "Bunny, lautloscrew.com" <bu...@lautloscrew.com> To: r-help@r-project.org Subject: [R] plm package index Message-ID: <9b6a22f4-5dd0-4fcd-9a6f-aee1e2108...@lautloscrew.com> Content-Type: text/plain Dear all, i just wonder if there´s a way to use a two column time index field in plm package. the manual says the following concerning data indexing: a character vector of length two containing the names of the individual and the time index, What would y´all do with a quarterly dataset that contains one column for the period and one for the year. Do I have to convert it to one single date field first ? thx in advance matt [[alternative HTML version deleted]] ------------- end original message --------------- Giovanni Millo Research Dept., Assicurazioni Generali SpA Via Machiavelli 4, 34132 Trieste (Italy) tel. +39 040 671184 fax +39 040 671160 ______________________________________________ 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.