Hi Marcelino, Was out of the office for a while... Thanks for the help. I think this could work...but can you tell me what this line does?
diversity <- apply(mol.tab,1,function(x) sum(x>0)) i cant figure out how diversity is calculated here? Thanks again for the help, matevz -----Original Message----- From: Marcelino de la Cruz [mailto:[email protected]] Sent: Thursday, May 12, 2011 2:03 PM To: Matevž Pavlič Cc: [email protected] Subject: Re: [R-sig-Geo] density /diversity of points On 12/05/2011 13:12, Matevž Pavlič wrote: > Hi all, > > > > I have a point data set (SHP) with coordinates and a attribute (i.e. type of > point). > > These points are scattered around a fairly big area. What i would like to do > is to find a sub-area where density of points sombined with the diversity of > type is the biggest. > > Does anyone have any idea iff this is somehowe possible to do in R? > Any idea would be greatly aprpeciated, > > To your first question: library(fortunes) fortune("Yoda") ;-) More seriously, you could transform your shp data in a ppp object with spatstat. See the vignette in spatstat. Then you can use some functions there, for example (with the data set lansing): library(spatstat) data(lansing) plot(lansing) # get an estimate of point density lansing.den <- density.ppp(lansing) plot(lansing.den) # get an estimate of point diversity (here, for the shake of brevity, at the points themselves) lansing.tab<- marktable(lansing,R=0.05) diversity <- apply(lansing.tab,1,function(x) sum(x>0)) lansing.div <- setmarks(lansing,diversity) lansing.div.s <-smooth.ppp(lansing.div) plot(lansing.div.s) # select areas with arbitrary high values of density and diversity plot(eval.im(lansing.div.s >4.5 & (lansing.den/max(lansing.den))>0.9)) HTH. Cheers, Marcelino -- _________________________________ Marcelino de la Cruz Rot Departamento de Biologia Vegetal E.U.T.I. Agricola Universidad Politecnica de Madrid 28040 Madrid Tel: 34913365654 _________________________________ _______________________________________________ R-sig-Geo mailing list [email protected] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
