Can your post a few lines of your data frame (e.g. via dput(head(...))) to make it clearer. I found this statement confusing: "... measurements stratified by the concentration of a certain substance. I would like to plot the points of the measures and connect the points within each series of concentrations."
This might or might not be the source of your problems, but I think showing us (enough of) your data would help clarify things. I don't use ggplot, but someone who does might have a better chance of pinpointing the problem if you provide such data. Cheers, Bert On Sat, Jul 1, 2023 at 11:21 AM Luigi Marongiu <marongiu.lu...@gmail.com> wrote: > > Hello, > I have a dataframe with measurements stratified by the concentration > of a certain substance. I would like to plot the points of the > measures and connect the points within each series of concentrations. > When I launch ggplot2 I get the error > ``` > geom_path: Each group consists of only one observation. Do you need to > adjust the > group aesthetic? > ``` > and no lines are drawn. > Where am I going wrong? > Thank you > Luigi > > ``` > df = data.frame(Conc = c(rep(1, 3), rep(2, 3), rep(5, 3)), > Time = rep(1:3, 3), > Value = c(0.91, 0.67, 0.71, 0.91, 0.65, 0.74, 0.95, 0.67, > 0.67)) > df$Time <- as.factor(df$Time) > levels(df$Time) = c(1, 4, 24) > df$Conc <- as.factor(df$Conc) > levels(df$Conc) = c(1, 2, 5) > library(ggplot2) > ggplot(df, aes(x=Time, y=Value, colour=Conc)) + > geom_point(size=6) + > geom_line(aes(x=Time, y=Value, colour=Conc)) + > scale_colour_manual(values = c("darkslategray3", "darkslategray4", > "deepskyblue4")) + > ggtitle("Working example") + > xlab(expression(bold("Time (h)"))) + > ylab(expression(bold("Concentration (mM)"))) > ``` > -- > Best regards, > Luigi > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.