Apparently, my brain cannot retain the R pch code index on its own. And I got tired of Google-Imaging (is that a legit verb?) “R pch” every time I needed to sort out a symbol. So I made a quick plot (mostly for my own use) of all the pch symbols (to add to the hundreds of others on the internet). So here it is.
The pch code is (somewhat obviously) the sum of the Y and X coordinates on the plot.
e.g. the @ symbol is pch=60+4 or 64.
Incidentally, I also came across this post on how to use unicode (hexidecimal) symbols on your R plots. Maybe there’s a Death Star symbol in there that I can sneak into a publication some time.
For the three of you who just must know how this is coded:
# Make the data pch.dat <- data.frame(expand.grid(X=1:10, Y=seq(0,250,10)), PCH=1:260) # Set up the plot window graphics.off() x11(w=7, h=11) par(mar=c(5,5,3,5)) # Make the plot plot(Y~X, data=pch.dat, type="n", axes=F)#, main="R pch = X + Y") abline(h=seq(0,250,10), col="gray90", lwd=20) abline(v=1:10, col="gray90", lwd=20) points(Y~X, data=pch.dat, pch=pch.dat$PCH, cex=1.2, col="black", bg="red") axis(1, at=1:10, las=1) axis(2, at=seq(0,250,10), las=1) axis(3, at=1:10, las=1) axis(4, at=seq(0,250,10), las=1) box() savePlot("R_pch_plot.png", type="png")