On Sat, 11 Feb 2006, mark shanks wrote: > Hi, > > I have a set of data in x,y coordinates across the range of -5 to 5 in each > dimension. I would like to obtain the frequency distribution of the > different points, and then graph them so you can see which of the points are > the most frequently occurring. > > This would seem to be easy in Matlab, which has the hist3 command for doing > frequency distributions/histograms in 3 dimensions. However, as far as I can > tell, R does not have a hist3 command.
See contributed package ash, function bin2: > xy <- cbind(x=runif(250,-5,5), y=runif(250,-5,5)) > bins <- bin2(xy, ab=matrix(c(-5,-5,5,5),2,2)) > image(bins$nc) or > filled.contour(bins$nc) Using the x and y arguments to image or filled.contour, you can set the axes, and asp=1 to preserve aspect. See also function kde2d in package MASS - included in the standard distribution. IMO, 3D histograms can mislead because perception depends on viewer position. All of the above give readily interpreted visualisations based on colour class intervals. > > Is there any easy way to do this in R? I'm investigating whether matlab or R > is more suitable for our needs, but don't want to reject R due to my present > ignorance of its functions. > > _________________________________________________________________ > realestate.com.au: the biggest address in property > http://ninemsn.realestate.com.au > > ______________________________________________ > [email protected] 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] ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
