Is there a grayscale equivalent to alpha levels in rgb? Example: I have the following to make red transparent circles overlap with previously plotted blue symbols.
symbols(x=sites$long,y=sites$lat,circles=log(sites$prop.nem +1),add=T,inches=F,bg=rgb(red=1,green=0,blue=0, alpha=0.5),fg=rgb(red=1,green=0,blue=0, alpha=0.5)) I'm having a hard time coming up with a grayscale equivalent. Thanks! ______________________________________________ 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.