On Thu, 9 Feb 2006, Tarmo Remmel wrote: > Dear List, > > I have examined the sp, maptools, and shapefiles packages (Windows) but > cannot seem to figure out a solution for writing shapefiles for 'curvy > shapes'. The scenario is that I generate a series of polygons, circles, and > ellipses on a plot and would like to convert them to shapefiles. Since the > circles and ellipses are do not return a coordinate list during the plotting > sequence (e.g., all I need supply are the lengths of axes and rotation > angle), is there an easy way by which the plot window can be converted to a > shapefile?
No, the plot window is committed to the device, and (re)-capturing the objects there as polygon objects will be messy. You'll need to generate an object that can be drawn as a sequence of straight line segments, and create a polygon object from that, from the x,y coordinates of the centre and the radius, or major/minor axes lengths and orientations. There is some code on: http://finzi.psych.upenn.edu/R/Rhelp02a/archive/56190.html (see RSiteSearch("circle")) but I don't know if it will suit your purposes. Once constructed, the polygons can be built into an object for exporting. > > Thank you, > > Tarmo > > __________________________________________ > Tarmo Remmel Ph.D. > GUESS Lab, Department of Geography > University of Toronto at Mississauga > Mississauga, Ontario, L5L 1C6 > Tel: 905-569-4382 > Lab: 905-828-3868 > Fax: 905-828-5273 > Skype: tarmoremmel > http://eratos.erin.utoronto.ca/remmelt > > ______________________________________________ > 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 > -- Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: [EMAIL PROTECTED] ______________________________________________ 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
