Dear Margaret, You've had one suggestion of an alternative for recoding variables, but in addition your code is in error (see below).
> -----Original Message----- > From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of > MACDOUGALL Margaret > Sent: Monday, October 10, 2016 10:56 AM > To: r-help@r-project.org > Subject: [R] Recoding lists of categories of a variable > > Hello > > The R code > mydata$newvar[oldvar = "topic1"] <- "parenttopic" That should be mydata$newvar[oldvar == "topic1"] <- "parenttopic" Moreover, the code assumes that oldvar is visible, which may not be the case if it lives in mydata and mydata isn't attach()ed. Best, John -------------------------------------- John Fox, Professor McMaster University Hamilton, Ontario, Canada Web: socserv.mcmaster.ca/jfox > > is intended to recode the category 'topic 1' of the old varaible > 'oldvar' a new category label 'parenttopic' by defining the new variable > 'newvar'. > > Is there a convenient way to edit this code to allow me to recode a list > of categories 'topic 1', 'topic 9' and 'topic 14', say, of the the old > variable 'oldvar' as 'parenttopic' by means of the new variable > 'newvar', while also mapping system missing values to system missing > values? > > Thanks in advance > > Best wishes > Margaret ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.