Hi, I've spent a while scrabbling around at this problem, to no avail. I'm sure there /should/ be a simple answer...
I have a large (14 million rows) data set, with two columns. Each row contains the number of times an individual moved, and the distance that individual moved in total. I would like a figure where the colour indicates the density of points, rather like this one my colleague produced in Matlab (with an older version of the data): http://www.warwick.ac.uk/~lssgah/warwick1.pdf Sadly, my colleague is away at the moment, so I can't find out what they did in Matlab. How should I be approaching this problem? [ideally, I'd like a colour-scale like that, too, but] My current approach, based on a bit in the back of Crawley's R book, was to create a new data file where I rounded distance off, and counted the number of similar rows to give a third column (a count). I then did: library(akima) obs <- read.table("numvsdistscount.dat") zz <- with(obs,interp(V1,V2,V3)) filled.contour(zz,col=heat.colors(12)) But: i) I think doing a rounding step to create the third column (separate from the plot generation) is unwise ii) This results in a shaded area less than the full area of the plot iii) The colour comes out almost uniform I'd be grateful for any pointers. Thanks, Matthew -- Matthew Vernon, Research Fellow Ecology and Epidemiology Group, University of Warwick http://blogs.warwick.ac.uk/mcvernon ______________________________________________ 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.
