# use the alpha argument of rgb or hsv to create transparent colours require(sp) xc <- round(runif(20), 2) yc <- round(runif(20), 2) xy <- cbind(xc, yc) xy.sp <- SpatialPoints(xy)
col1 <- hsv(h = (1:10)/80, v = 0.9, alpha = 0.3) col2 <- hsv(h = 0.25+(1:10)/50, v = 0.8, alpha = 0.4) plot(xy.sp[1:10,], pch = 21, col = "red", cex = 20, bg = col1) points(xy.sp[11:20, ], pch = 21, col = "darkgreen", cex = 10, bg = col2) # Happy Christmas! Chris Campbell MANGO SOLUTIONS Data Analysis that Delivers +44 1249 767700 -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Ana Sent: 28 December 2011 12:13 To: r-help@r-project.org Subject: [R] transparency using plot+points with sp classes 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. LEGAL NOTICE This message is intended for the use o...{{dropped:10}} ______________________________________________ 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.
