2010/12/21 Petr PIKAL : > Hi > > r-help-bounces@r-project.org napsal dne 21.12.2010 11:02:07: > >> Hello, >> >> I am trying to analyze sociological survey data using R. It is often >> important in survey to calculate both the actual factor sums and >> percentages (easily done with describe() ), but also the numbers and >> total percentage of NA's. Often it is important to present NA's in >> graphs besides the factors. >> >> Is there any easy way to make R treat NA's as if those were factors >> besides other factors? >> >> Now, describe(data$a) gives me percentages only for the factors. So I >> have to redo percentages manually. >> >> barplot() also ignores NA's. So, to include NA's into barplot I need >> to do a table more or less manually. >> >> The other way to do it is to convert NA's into factors (doable, >> although, unlike in SPSS, I cannot make an assumption that 99 is a > > not necessary to code missing values, you can set NA as one level. > > x<-factor(sample(c(1:3, NA),20,replace=T), exclude=NULL) > x >  [1] 1    1    3    3    3    2    3     3    1    2     3     > 2 > [16] 2    3    1     3 > Levels: 1 2 3 >> y<-rnorm(20) > boxplot(split(y,x)) > > Besides you could find it from factor help page as I did. > > Regards > Petr Thank you Petr, this info (re exclude=NULL) might have saved me tons of time last week :) I still have not found an equivalent parameter in describe(), but anyway, I have been helped a lot! -- Donatas Glodenis ______________________________________________ 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.