I've a data frame with this structure: 'data.frame': 1987 obs. of 11 variables: $ site : Factor w/ 24 levels "B(W)","BC-1",..: 1 1 2 2 2 1 1 1 ... $ sampdate : Date, format: "2000-07-18" "2000-07-18" ... $ tclass : Factor w/ 8 levels "Annelida","Arachnida",..: 1 5 5 5 5 ... $ torder : Factor w/ 18 levels "Achtinedida",..: 13 5 5 10 13 5 7 ... $ tfamily : Factor w/ 81 levels "","Ameletidae",..: 79 46 46 14 42 ... $ tgenus : Factor w/ 206 levels "","Acentrella",..: 1 10 10 1 140 ... $ tspecies : Factor w/ 60 levels "","aequalis",..: 1 1 1 1 1 1 1 ... $ quant : int 22 527 22 22 11 97 333 11 108 11 ... $ stream : Factor w/ 7 levels "BCrk","JCrk",..: 1 1 1 1 1 1 1 1 ... $ basin : Factor w/ 2 levels "H","O": 2 2 2 2 2 2 2 2 2 2 ...
When I create a bar chart for tclass by stream the resulting bars appear to have multiple segments (see attached pdf) from this command: barchart(quant ~ tclass | stream, data = benthos, main = 'Taxonomic Classes', xlab = 'Class Name', ylab = 'Number/square meter', scales = list(x = list(rot = 90))) and I want to understand what the segments represent. I thought the formula 'quant ~ tclass' would produce one bar per class. I cannot find the answer in the ?barchart help page (it may be there and I'm not seeing it) or the Lattice book. Your help in increasing my understanding is appreciated. TIA, Rich
class-by-stream.pdf
Description: Adobe PDF document
______________________________________________ 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.
