Dear Sarah, RE:
> Hi all, > > I'm working with a bunch of large graphs, and stumbled across > something useful. Probably many of you know this, but I didn't and so > others might benefit. > > Using pch="." speeds up plotting considerably over using symbols. > >> x <- runif(1000000) >> y <- runif(1000000) >> system.time(plot(x, y, pch=".")) > user system elapsed > 1.042 0.030 1.077 >> system.time(plot(x, y)) > user system elapsed > 37.865 0.033 38.122 > > If you have enough points, the result is also more legible. > > Choice of which pch symbol makes a difference too, the default pch=1 being > the slowest of what I tried, but "." is by far the speediest. > >> system.time(plot(x, y, pch=0)) > user system elapsed > 11.191 0.011 11.270 >> system.time(plot(x, y, pch=1)) > user system elapsed > 38.024 0.008 38.245 >> system.time(plot(x, y, pch=2)) > user system elapsed > 14.140 0.027 14.270 >> system.time(plot(x, y, pch=3)) > user system elapsed > 15.696 0.011 15.799 >> system.time(plot(x, y, pch=4)) > user system elapsed > 18.770 0.007 18.888 > > This is a vanilla R session, 2.13.1 for x86_64-redhat-linux-gnu. I > haven't tried it on any other OS, but it's making my life a lot > smoother right now. > > Sarah With Mac OS10 (Snow Leopard, MacBookPro, R version 2.14.0), it 's a bit different: 2.14) source("/var/folders/t6/t6uCNQmsHsSw6tS6HuHp4U+++TI/-Tmp-//Rtmp4ZzIWp/file6b861d06") [1] "plot symbol . (dot)" user system elapsed 16.620 0.087 16.731 [1] "plot symbol default (circle)" user system elapsed 53.132 0.134 52.959 [1] "symbol# 0" user system elapsed 18.828 0.090 18.803 [1] "symbol# 1" user system elapsed 53.046 0.134 52.877 [1] "symbol# 2" user system elapsed 22.000 0.154 22.401 [1] "symbol# 3" user system elapsed 20.794 0.096 20.763 [1] "symbol# 4" user system elapsed 23.534 0.098 23.542 It seems that even-numbered symbols are plotted faster than the odd ones By the way, I learn a lot about R programming by just following r-help! Best regards, Franklin Bretschneider -- Dept Biologie Kruytgebouw W711 Padualaan 8 3584 CH Utrecht The Netherlands -- f.bretschnei...@uu.nl ______________________________________________ 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.