Proper Syntax for Logical Subset in Subset()
On Wed, 2 Nov 2011, Bert Gunter wrote:
To make such a plot, I would have thought your want your data structure to be:
Column A: Date Column B; Chemical Column C: Result
Thanks, Bert. I have a data frame in that format.
After subsetting this to the chemicals you want or doing the subsetting in
your plot command, something like (base R)
boxplot(Result ~ Chemical, subset=yourdat$Chemical %in% c("Ca","Cl",
"Cond","Mg","Na","SO2","TDS"))
Great! I'll work with this. I tend to use lattice so I can learn its capabilities better.
Whether I'm correct or not in my understanding of your situation, an important message is: you should choose your data structure to facilitate the analysis that you have in mind. IMHO, this is one of R's great strengths: it provides rich facilities for manipulating data tightly integrated with plotting and analytical capabilities.
I recognize this and continue to learn how best to represent the same data for different analyses and plots. Much appreciated, Rich