On 09-Sep-10 06:41:34, Rainer Machne wrote: > Hi, > does anybody know of some plotting function or an easy way to > generate "+" symbols with individually settable bar lengths? > I tried just combining "|" and "-" as pch and setting the size via cex, > but that doesn't really work since the two symbols have different > default lengths. Is there a horizontal | or a longer "-" available? > > Thanks, > Rainer
I tried this using pch="_" for the horizontal bar, but it is only about half the length of the pch="|" bar. However, compared with the same plot using pch="+", at least the resulting cross went through the centre of the "+" cross. To increase the length of the "_" to equal that of the "|" would require some empirical fiddling with 'cex=..." and would increase the thickness of the "_". I don't know of any way to create a symbol using drawing commands, and assigning the result to a "character" which could be evoked using 'pch="..."', which would seem to be the sort of thing you would like to be able to do. This could be a useful extension to the plot() function and friends. You can of course define an auxiliary function, say mycross(), on the lines of mycross <- function(x,y,L,U,R,D){ lines(c(x,x-L),c(y,y)) lines(c(x,x),c(y,y+U)) lines(c(x,x+R),c(y,y)) lines(c(x,x),c(y,y-D)) } but then you would have to explicitly apply this to the data, rather than delegate it to the plot() function's pch option. Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <ted.hard...@manchester.ac.uk> Fax-to-email: +44 (0)870 094 0861 Date: 09-Sep-10 Time: 08:36:36 ------------------------------ XFMail ------------------------------ ______________________________________________ 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.