I have a data frame called chemdata with this structure:
str(chemdata)
'data.frame': 14886 obs. of 4 variables: $ site : Factor w/ 148 levels "BC-0.5","BC-1",..: 104 145 126 115 114 128 124 2 3 3 ... $ sampdate: Date, format: "1996-12-27" "1996-08-22" ... $ param : Factor w/ 8 levels "As","Ca","Cl",..: 1 1 1 1 1 1 1 1 1 1 ... $ quant : num 0.06 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 ... I've looked in the R Cookbook and Dalgaard's intro book without finding a way to use wildcards (e.g., like "BC-*") or explicitly witing each site ID when subdsetting a data frame.. I need to create subsets (as data frames) based on sites, but including all sites on each stream. For example, using the initial site factor shown above, I want a subset containing all data for sites "BC-0.5", "BC-1". "BC-2", "BC-3", "BC-4", "BC-5", and "BC-6". Pointers appreciated, 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.
