Paulo Barata wrote: > Dear R-list members, > > I would like to draw a smooth arc. I can draw an arc > parametrically, but this produces an arc too coarse, > even allowing for different increments in sequence t > in the example below. Function "symbols" (graphics) does > produce a smooth circle, but it cannot produce an arc. > > Please see the following example, drawing complete circles: > > plot(-5:5,-5:5,type='n') > ## draws circle with function symbols (package graphics) > ## - inner circle is very smooth: > symbols(0,0,circles=2,add=TRUE) > ## draws circle parametrically - outer circle is too coarse: > pi <- 4*atan(1) > t <- seq(0,2*pi,0.02) > lines(4*cos(t),4*sin(t)) > > Package "plotrix" has a function "draw.arc", but arcs produced > with this function are also either too coarse or too polygonal, > depending on the number of polygons used to approximate the arc. > > Is there a way to harness the characteristics of function > "symbols" (graphics) to draw a smooth arc, not just a complete > circle? > Hi Paulo, I may be misunderstanding you, but have you tried to increase the number of segments in the arc using the "n" argument?
draw.arc(1,1,1,n=100) Jim ______________________________________________ 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.