Try this: table(rep(x$age, unlist(lapply(strsplit(x$favorite_magazine, ","), length))), unlist(strsplit(x$favorite_magazine, ",")))
On Mon, Sep 29, 2008 at 11:45 AM, June Kim <[EMAIL PROTECTED]> wrote: > Hello, > > I use google docs' Forms to conduct surveys online. Multiple choices > questions are coded as comma separated values. > > For example, > > if the question is like: > > 1. What magazines do you currently subscribe to? (you can choose > multiple choices) > 1) Fast Company > 2) Havard Business Review > 3) Business Week > 4) The Economist > > And if the subject chose 1) and 3), the data is coded as a cell in a > spreadsheet as, > > "Fast Company, Business Week" > > I read the data with read.csv into R. To analyze the data, I have to > change that string into something like flags(indicator variables?). > That is, there should be 4 variables, of which values are either 1 or > 0, indicating chosen or not-chosen respectively. > > Suppose the data is something like, > >> survey1 > age favorite_magazine > 1 29 Fast Company > 2 31 Fast Company, Business Week > 3 32 Havard Business Review, Business Week, The Economist >> > > Then I have to chop the string in favorite_magazine column to turn > that data into something like, > >> survey1transformed > age Fast Company Havard Business Review Business Week The Economist > 1 29 1 0 0 0 > 2 31 1 0 1 0 > 3 32 0 1 1 1 >> > > Actually I have many more multiple choice questions in the survey. > > What is the easy elegant and natural way in R to do the job? > > ______________________________________________ > 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. > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O ______________________________________________ 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.