Dear Paul, This looks like a version of the question you asked a couple of weeks ago. As I explained then, I'm pretty sure that you want concentration (i.e., data) ellipses and not confidence ellipses, which pertain to parameters (e.g., regression coefficients). Also, the hand-drawn concentration contours in your example graph don't look elliptical, so I'm not sure that you really want ellipses, but I'll assume that you do. Since as far as I can see you didn't share your data, here's a similar example using the scatterplot() function in the car package: library("car") scatterplot(prestige ~ income | type, data=Prestige, ellipse=TRUE, smooth=FALSE, regLine=FALSE) By default, this draws 50% and 95% concentration ellipses assuming bivariate normality in each group, but that and other aspects of the graph can be customized -- see ?scatterplot. I hope this helps, John -- John Fox, Professor Emeritus McMaster University Hamilton, Ontario, Canada web: https://socialsciences.mcmaster.ca/jfox/ On 2022-01-24 4:24 p.m., Paul Bernal wrote:> Dear friends, > > I will be sharing a dataset which has the following columns: > 1. Scenario > 2. Day of Transit date > 3. Canal Ampliado > 4. Canal Original > > Basically, I need to create a scatter plot diagram, with the Canal Ampliado > column values in the x-axis, and the Canal Original column values in the > y-axis, but also, I need to create confidence interval ellipses grouping > the points on the scatterplot, based on the different scenarios. > > So I need to have in one graph, the scatterplot of Canal Ampliado vs Canal > Original and then, on the same graph, construct the confidence interval > ellipses. > > I will attach an image depicting what I need to accomplish, as well as the > dataset, for your reference. > > Any help and/or guidance will be greatly appreciated. > > Cheers, > Paul > > > ______________________________________________ > R-help at 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.