Hi, I have:
hours=c(5,6,6,7,7,8,8,9,7,8,8,8,9,9,10,10,9,10,10,11,11,11,12); level=c(1.0,1.2,0.8,0.8,1.0,1.0,0.6,0.8,1.4,1.2,1.4,1.6, 1.2,1.4,1.0,1.4,1.6,1.6,1.8,1.4,1.6,1.8,1.6); grade=c(rep("First",8),rep("Second",8),rep("Third",7)) length(hours) length(level) length(grade) data=data.frame(hours=hours,level=level,grade=grade) data plot(data$hours,data$level) Without using ggplot, just using core basic R, how can I: 1. Color each point according to the grade factor. 2. Select a different point type according to the grade factor. Thanks. D. -- View this message in context: http://r.789695.n4.nabble.com/Scatterplot-Color-by-Grade-Category-tp4659135.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.