On Tue, 1 May 2007, Greg Snow wrote: > Here is an approach that clips the circle you like from symbols down to > an arc (this will work as long as the arc is less than half a circle, > for arcs greater than half a circle, you could draw the whole circle > then use this to draw an arc of the bacground color over the section you > don't want): > > library(TeachingDemos) > plot(-5:5, -5:5, type='n') > clipplot( symbols(0,0,circles=2, add=TRUE), c(0,5), c(0,5) )
I had considered this approach: clipping a circle to a rectangle isn't strictly an arc, as will be clear if the line width is large. Consider clipplot(symbols(0, 0 ,circles=2, add=TRUE, lwd=5), c(-1,5), c(-1,5)) Note too that what happens with clipping is device-dependent. If R's internal clipping is used, the part-circle is converted to a polygon. -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-help@stat.math.ethz.ch 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.