Hello all. Let's say I have a multivariate time-series, obtained from 2 loggers returning a numeric value and a factor giving additional information about this numeric value, for instance its accuracy: data<-data.frame(date=rep(seq(from=as.Date("2012-01-01"), by=1, length.out=100), 2), logger=c(rep("logger1",100), rep("logger2", 100)), value=rnorm(200), accuracy=rep(c(rep("poor", 25), rep("good", 50), rep("poor", 25)),2)) I would like to plot this time-series using ggplot2, with one facet per logger, and using colour to show the accuracy class: ggplot(data, aes(date, value, colour=accuracy))+geom_line()+facet_wrap(~logger) <http://r.789695.n4.nabble.com/file/n4673535/Rplot.jpeg> The problem is that ggplot2 actually plots 2 discontinuous time-series in each facet (one for each accuracy class), which results in straight lines across the plot, and line breaks between different accuracy classes. Of course I could create 4 time-series with the same index, padding them with NAs to get rid of the straight lines, but this would not get rid of the line breaks, and, since the actual data have many more possible logger x accuracy combinations, I was wondering if there was an easier and quicker way? Many thanks Arnaud -- View this message in context: http://r.789695.n4.nabble.com/Plotting-multivariate-time-series-with-ggplot2-tp4673535.html Sent from the R help mailing list archive at Nabble.com.