The data set (called 'chemdata') has 6 columns (4 factors, 1 date, 1 numeric) and I need to create subsets for each of one of the factors ('stream'). This has worked flawlessly for all but two streams which were created yesterday.
The command I use to create the subsets is like this:
rnchH <- subset(chemdata, stream == 'RanchSpgsH', select = c(site, sampdate,
param, quant), drop = T) but it does not copy the dates in 'sampdate' for this and one other subset:
str(rnchH)
'data.frame': 0 obs. of 4 variables: $ site : Factor w/ 138 levels "BC-0.5","BC-1",..: $ sampdate:Class 'Date' num(0) $ param : Factor w/ 58 levels "AGP","ANP","ANP/AGP",..: $ quant : num The source for chemdata (accessed by read.table()) has dates for this stream; e.g., RNCHS|1994-03-23|pH|7.66|RanchSpgsH|H RNCHS|1994-01-20|pH|7.66|RanchSpgsH|H If I use the same command on a different stream the sampdate column contains the dates:
b2 <- subset(chemdata, stream == 'BurnsCrk', select = c(site, sampdate,
param, quant), drop = T)
str(b2)
'data.frame': 2472 obs. of 4 variables: $ site : Factor w/ 138 levels "BC-0.5","BC-1",..: 5 5 5 5 5 5 5 5 5 ... $ sampdate: Date, format: "1992-03-27" "1992-04-30" ... $ param : Factor w/ 58 levels "AGP","ANP","ANP/AGP",..: 37 37 37 37 ... $ quant : num 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 8.08 ... I keep looking to see why the first fails but have not found it. Pointers on where to look will be helpful. TIA, 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.