How can I make one point graphics with transparency These are all sp classes:
plot(polygons_area,axes=TRUE,asp=1.5,main="Title",xlab="Latitude", ylab="Longitude") points(observations2000,type = "p",pch=21,col="green") points(observation1999,type = "p",pch=21,col="blue") points(reference.points,type = "p",pch=21,col="red") how can I add transparency to one of the point graphics, for example points(observation1999,type = "p",pch=21,col="blue") ? ______________________________________________ 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.
