[R-sig-eco] Dissimilarity ranking

[Gavin Simpson]

On Tue, 2010-11-23 at 15:43 -0500, Steve_Friedman at nps.gov wrote:
> Burak
> 
> You should explore the use of non-metric multidimensional scaling.
> 
> ?cmdscale

cmdscale is classical (or metric) multidimensional scaling. nMDS is in
MASS:::isoMDS() or vegan's metaMDS().

G

> Steve Friedman Ph. D.
> Ecologist  / Spatial Statistical Analyst
> Everglades and Dry Tortugas National Park
> 950 N Krome Ave (3rd Floor)
> Homestead, Florida 33034
> 
> Steve_Friedman at nps.gov
> Office (305) 224 - 4282
> Fax     (305) 224 - 4147
> 
> 
>                                                                            
>              "Pekin, Burak K"                                              
>              <bpekin at purdue.ed                                             
>              u>                                                         To 
>              Sent by:                  "'r-sig-ecology at r-project.org'"     
>              r-sig-ecology-bou         <r-sig-ecology at r-project.org>       
>              nces at r-project.or                                          cc 
>              g                                                             
>                                                                    Subject 
>                                        [R-sig-eco] Dissimilarity ranking   
>              11/23/2010 03:09                                              
>              PM                                                            
>                                                                            
>                                                                            
>                                                                            
>                                                                            
> 
> 
> 
> 
> Hello, I want to rank the dissimilarity of sites based on their species
> composition. For example, I would like to be able to say that site A is
> less similar in composition to the other sites than site B is similar to
> the other sites. I could do a cluster analysis and look at which sites are
> less closely clustered.
> 
> It would be even better if I could come up with a quantitative scale rather
> than a relative ranking that would give a value for each site based on its
> relative dissimilarity to the rest of the sites. So site A might receive a
> 90 out of 100, whereas site B and C might receive a 60 and a 50 indicating
> the rank as well as 'relative quantity' of dissimilarity for each site.
> 
> Thanks,
> Burak
> 
> --------------------------
> 
> Burak K. Pekin, PhD
> Postdoctoral Research Associate
> Purdue University
> 
> 
>              [[alternative HTML version deleted]]
> 
> _______________________________________________
> R-sig-ecology mailing list
> R-sig-ecology at r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-ecology
> 
> _______________________________________________
> R-sig-ecology mailing list
> R-sig-ecology at r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-ecology

-- 
%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%
 Dr. Gavin Simpson             [t] +44 (0)20 7679 0522
 ECRC, UCL Geography,          [f] +44 (0)20 7679 0565
 Pearson Building,             [e] gavin.simpsonATNOSPAMucl.ac.uk
 Gower Street, London          [w] http://www.ucl.ac.uk/~ucfagls/
 UK. WC1E 6BT.                 [w] http://www.freshwaters.org.uk
%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%