Some like this help? mydata$modnew <- cut(mydata$moderator, 7) ggplot(mydata, aes(x=predictor, y=outcome, color=modnew)) + geom_point() + stat_smooth(method=lm, se=TRUE, fullrange=T)
John Kane Kingston ON Canada > -----Original Message----- > From: dadr...@gmail.com > Sent: Wed, 26 Sep 2012 09:45:07 -0400 > To: r-help@r-project.org > Subject: [R] Interaction scatterplots in ggplot with multiple regression > lines > > I'm trying to treat a continuous variable as discrete for plotting > multiple regression lines in a scatterplot as a function of the level > on the moderating variable. In the example below, there is only one > regression line plotted to the whole data. I would like a separate > regression line for each discrete level of the moderator. The > moderator is continuous, so I'd like to treat it as discrete for > plotting the regression lines. > > Here's an example (I would like 7 regression lines corresponding to > the discrete levels of the moderator, as displayed in the legend, > instead of just 1 regression line): > > ########################### > library(ggplot2) > set.seed(1234) > predictor <- rnorm(1000, 3) > outcome <- rnorm(1000, 10) > moderator <- rnorm(1000) > mydata <- data.frame(predictor, outcome, moderator) > > ggplot(mydata, aes(x=predictor, y=outcome, color=moderator)) + > geom_point() + scale_colour_gradient2(low="blue", high="red") + > stat_smooth(method=lm, se=TRUE, fullrange=T) > ########################### > > Also, how can I set how many discrete levels to plot (e.g., 3 instead of > 7)? > > Thanks in advance! > > ______________________________________________ > 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. ____________________________________________________________ FREE 3D EARTH SCREENSAVER - Watch the Earth right on your desktop! ______________________________________________ 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.