Hi Sarah, Thanks you for the clarifications; I had worked round the problem by switching to a data.frame.
However, I am still unclear about 'list': as it exists, it must have a purpose. When is the use of the list data structure appropriate? [[alternative HTML version deleted]]
______________________________________________ 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.