# Need frequency distribution for x,y coordinates

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## Need frequency distribution for x,y coordinates

 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. 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______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
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## Re: Need frequency distribution for x,y coordinates

 Check out: http://addictedtor.free.fr/graphiques/graphcode.php?graph=116On 2/11/06, mark shanks <[hidden email]> 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. > > 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> > ______________________________________________ > [hidden email] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html> ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
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## Re: Need frequency distribution for x,y coordinates

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## Re: Need frequency distribution for x,y coordinates

 On Sat, 11 Feb 2006, Roger Bivand wrote: > On Sat, 11 Feb 2006, mark shanks wrote: > >> 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. And density plots are usually a lot better than histograms for understanding 2D data. > IMO, 3D histograms can mislead because perception depends on viewer > position. All of the above give readily interpreted visualisations based > on colour class intervals. But if you really want one, see demo("hist3d") in package rgl, which allows you to change your position interactively and uses translucency. >> 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. -- Brian D. Ripley,                  [hidden email] Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/University of Oxford,             Tel:  +44 1865 272861 (self) 1 South Parks Road,                     +44 1865 272866 (PA) Oxford OX1 3TG, UK                Fax:  +44 1865 272595 ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide! http://www.R-project.org/posting-guide.html