>> I disagree. Grey levels suck; labels are a kludge. It is an issue >> for ``many'' == 2, for which crosshatching works perfectly. >> > > Could you show an example? > > There are several BW examples in example(barplot), and the gray ones look > better on screen than the cross-hatched one. (Not to say it makes a very > good choice of cross-hatching, but I suspect the gray examples will look > better than any 5 cross-hatch patterns.) I haven't tried printing the > examples, so I'm not sure the gray would reproduce well on paper; I wouldn't > try to print those 5 gray levels on a typical printer.
My feeling is that the best cross-hatching is probably going to be more aesthetically pleasing than the best solid greys (see e.g. http://www.dannygregory.com/2005/09/cross_hatching.php). However, doing cross hatching well is far more difficult than doing grey well, and for really nice cross-hatching I suspect you also need a high quality printer. It is also a challenging problem to come up with an algorithm for generating perceptually uniform sets of cross-hatchings. I suspect there is some work on this area in vis/infovis, but I haven't find it in a few minutes of casual searching. Hadley Hadley -- http://had.co.nz/ ______________________________________________ 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.