A data frame is a list of vectors of the same length. A list is a vector. So is it acceptable to use a list as a column of a data frame?
I'd like to be able to take advantage of all the nice features of data frames (esp. subsetting) while storing more complicated objects. An example of this would be a version of by that returns a data.frame instead of a list - you would then be able to extract the objects you wanted using subsetting, rather than having to loop through each element of the list and see if it matches your criteria. I have been experimenting a bit with this, and generally it works fine (apart from the occasional bug with printing, and not being able to use data.frame(a=1, list(a=1, b=2)) because of the way as.data.frame.list works). Is it ok to do this? ie. if it works in the current version of R, should I expect it to keep working in the future? Is it undocumented because it is obvious, or because it's a bad idea? Thanks, Hadley ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html