Agustin Lobo wrote: > Dear list: > > Given > > str(b3) > 'data.frame': 159 obs. of 6 variables: > $ index_pollution : num 8.228 10.513 0.549 0.915 10.416 ... > $ position_descrip: chr "2" "2" "2" NA ... > $ position_geo : chr "3" "0" "3" "3" ... > $ institution : Factor w/ 3 levels "digesa","mem",..: 3 3 3 3 3 3 > 3 3 3 3 ... > $ p_desc_no3 : chr "2" "2" "2" NA ... > $ p_geo_no3 : chr "3" "0" "3" "3" ... > > I try to subscript but get: > > > b3[b3[,3]=="3",5] <-NA > Error in `[<-.data.frame`(`*tmp*`, b3[, 3] == "3", 5, value = NA) : > missing values are not allowed in subscripted assignments of data > frames Notice that it is not the NA on the right that is the problem, but those in the subscript, so try
b3[b3[,3]=="3" | is.na(b3[,3]), 5] <- NA (or ... &!is.na... if that is what you want) > Why? What's the correct way of doing this operation? I forget the exact reason, but as far as I remember, we allowed it at some point, but found that behaviour was inconsistent between differnt modes of subassignment. > Actually, I previously tried with: > > str(b2) > 'data.frame': 159 obs. of 6 variables: > $ index_pollution : num 8.228 10.513 0.549 0.915 10.416 ... > $ position_descrip: Factor w/ 3 levels "0","1","2": 3 3 3 NA NA NA 3 > 3 3 3 ... > $ position_geo : Factor w/ 4 levels "0","1","2","3": 4 1 4 4 3 NA > 3 3 3 4 ... > $ institution : Factor w/ 3 levels "digesa","mem",..: 3 3 3 3 3 3 > 3 3 3 3 ... > $ p_desc_no3 : Factor w/ 3 levels "0","1","2": 3 3 3 NA NA NA 3 > 3 3 3 ... > $ p_geo_no3 : Factor w/ 4 levels "0","1","2","3": 4 1 4 4 3 NA > 3 3 3 4 ... > > > table(b2$p_desc_no3) > > 0 1 2 > 42 44 66 > > and > > > levels(b2$p_desc_no3)[levels(b2$position_geo)=="3"] <- NA > > which does not result into error but leaves b2$p_desc_no3 unchanged: > I don't think this makes sense at all. It changes the 4th level of a three-level factor??? > > table(b2$p_desc_no3) > > 0 1 2 > 42 44 66 > > > what am i doing wrong? > > Thanks > > Agus > > > -- O__ ---- Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 ______________________________________________ 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.
