Hi James, Specify data = times in the qplot call and get rid of times$ everywhere. For example, do
pp2 = qplot(time, error, data = times) pp2 + facet_wrap(~ runway) Best, Ista On Tue, Jun 7, 2011 at 4:01 PM, James Rome <jamesr...@gmail.com> wrote: > I have a data frame (attached) that has interpolated EOT errors for > each minute before flight landing. It also has the runway and an index > for the flight: > >> > times[1:4,] > time error runway flight > 1 0 -0.02206235 04R 1 > 2 1 -0.07961631 04R 1 > 3 2 -0.13795380 04R 1 > 4 3 -0.20726073 04R 1 > >> > sapply(times, class) > time error runway flight > "numeric" "numeric" "factor" "factor" > > I want to plot this using ggplot2 > library(ggplot2) > pp2 = qplot(times$time, times$error, times) > pp2 = pp2 + facet_wrap(~ times$runway) > print(pp2) > But when I try it, I get the error > Error in fix.by(by.x, x) : 'by' must specify valid column(s) > I get the same error if I make times$time a factor: > >> > times$time = as.factor(times$time) >> > sapply(times, class) > time error runway flight > "factor" "numeric" "factor" "factor" > >> > pp2 = qplot(times$time, times$error, times) >> > pp2 = pp2 + facet_wrap(~ times$runway) >> > print(pp2) > Error in fix.by(by.x, x) : 'by' must specify valid column(s) > > What am I doing wrong? > > And I really want to make a boxplot for every minute of times$time, but > when I try that, I get one single box. > > Thanks for the help, > Jim > > > ______________________________________________ > 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. > > -- Ista Zahn Graduate student University of Rochester Department of Clinical and Social Psychology http://yourpsyche.org ______________________________________________ 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.