Hi, It seems that anti-aliasing in png(type = 'cairo') is not well supported for the point symbols without boarders, e.g. pch = 16. The Cairo package works well, though. You can compare png() with CairoPNG():
png(): http://i.imgur.com/8niB3jX.png CairoPNG(): http://i.imgur.com/FZBJOxm.png f = function(dev, ..., main = '') { dev(...) plot(c(1, 2, 1, 2), c(1, 1, 2, 2), pch=c(16, 19), cex=c(2, 2, 15, 15), xlim=c(0.5, 2.5), ylim=c(0.5, 3), main = deparse(substitute(dev))) dev.off() } f(grDevices::png, 'png-base.png', type = 'cairo') f(Cairo::CairoPNG, 'png-Cairo.png') If I remove the border for pch=19 (i.e. lwd=0), the point shows rough edges as well. I'm not sure if that is expected, or it is due to my misconfiguration somewhere. I installed R via `apt-get install r-base-dev` under Ubuntu using the CRAN repository. > sessionInfo() R version 3.0.2 (2013-09-25) Platform: x86_64-pc-linux-gnu (64-bit) locale: [1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C LC_TIME=en_US.UTF-8 LC_COLLATE=en_US.UTF-8 [5] LC_MONETARY=en_US.UTF-8 LC_MESSAGES=en_US.UTF-8 LC_PAPER=en_US.UTF-8 LC_NAME=C [9] LC_ADDRESS=C LC_TELEPHONE=C LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C attached base packages: [1] stats graphics grDevices utils datasets methods base loaded via a namespace (and not attached): [1] Cairo_1.5-2 tools_3.0.2 > capabilities() jpeg png tiff tcltk X11 aqua http/ftp sockets TRUE TRUE TRUE TRUE TRUE FALSE TRUE TRUE libxml fifo cledit iconv NLS profmem cairo TRUE TRUE TRUE TRUE TRUE TRUE TRUE Regards, Yihui -- Yihui Xie <xieyi...@gmail.com> Web: http://yihui.name Department of Statistics, Iowa State University 2215 Snedecor Hall, Ames, IA ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel