On Fri, 21 Oct 2011, David Winsemius wrote:
How are we to determine which lines contain information about the "relationships" of param=="TDS" with whatever cases or variable has values of "Cond" and "SO4"? Are you really trying to compare two disjoint groups on some statistic like the means and std-dev of "quant"? (This would be a job for `aggregate`.)
When I try to select rows based on non-null contents for two values of 'param' I don't have the correct syntax. Perhaps I need to use multiple data frames instead of a single one? Rich ______________________________________________ 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.
