I googled a bit and found that cairo needs to be installed on Ubuntu. Through Ubuntu package manager, I installed package r-cran-cairodevice, but that doesn't seem to solve the problem.
Aditya On Thu, Jan 27, 2011 at 10:43 AM, Aditya Bhagwat <bhagwatadi...@gmail.com>wrote: > Dear Prof. Ripley, > > Thanks for your reply. > > This is one of the main points of supporting semi-transparent colours. >> You haven't told us your platform or graphics device (see the posting >> guide), but plotting with something like col=rgb(0,0,0,0.2) may work. > > > I am working on Ubuntu Linux. and I tried the suggested approach but got an > empty plot and the following warning message: > In plot.xy(xy, type, ...) : > semi-transparency is not supported on this device: reported only once per > page > > Any suggestions on how to proceed? > > Many thanks, > > Aditya > > > >> >> On Thu, 27 Jan 2011, Aditya Bhagwat wrote: >> >> Dear all, >>> >>> When making a plot with the command plot(xVector, yVector), there are >>> many >>> points that collide on the same place in the plot. In order to make this >>> plot clearer, I have been looking for a way to colour the points based on >>> the number of points that fall onto each other. If only one point falls >>> on a >>> particular location, make it gray, if many points fall, make it black. >>> >>> I tried to search the help archives, but didn't find any useful answers. >>> Anyone has any suggestion? >>> >>> Many thanks for your help! >>> >>> Aditya >>> >>> -- >>> Aditya Bhagwat >>> >>> [[alternative HTML version deleted]] >>> >>> ______________________________________________ >>> 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. >>> >>> >> -- >> Brian D. Ripley, rip...@stats.ox.ac.uk >> Professor of Applied Statistics, >> http://www.stats.ox.ac.uk/~ripley/<http://www.stats.ox.ac.uk/%7Eripley/> >> University of Oxford, Tel: +44 1865 272861 (self) >> 1 South Parks Road, +44 1865 272866 (PA) >> Oxford OX1 3TG, UK Fax: +44 1865 272595 >> > > > > -- > Aditya Bhagwat > > > -- Aditya Bhagwat [[alternative HTML version deleted]] ______________________________________________ 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.