On Tue, 3 Jan 2012, David Winsemius wrote:
That's rather unconvincing. What does this show: burns.tds[ !duplicated(burns.tds) ]
I saw that in the help page but assumed it was the opposite of duplicated; apparently not. burns.tds[ !duplicated(burns.tds) ] Error in .data.frame(burns.tds, !duplicated(burns.tds)) : undefined columns selected burns.tds was generated by burns.tds <- subset(chemdata, stream == 'BurnsCrk', select = c(site, sampdate, param == 'TDS', quant), drop = T) and has this structure 'data.frame': 2472 obs. of 3 variables: $ site : Factor w/ 137 levels "BC-0.5","BC-1",..: 5 5 5 5 5 5 5 5 ... $ sampdate: Factor w/ 1056 levels "1978-03-28","1978-04-11",..: 155 156 158 161 163 164 172 175 177 309 ... $ quant : num 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 8.08 ... Because the data frame chemdata came from a relational table with a primary key of (site, sampdate, param) I am having trouble understanding where duplicate rows could have originated. Thanks, David, 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.
