Clustering with ordinal data

Steve -
    Take a look at daisy() in the cluster package.

 					- Phil Spector
 					 Statistical Computing Facility
 					 Department of Statistics
 					 UC Berkeley
 					 spector at stat.berkeley.edu

Hello

I've been asked to help evaluate a vegetation data set, specifically to
examine it for community similarity. The initial problem I see is that the
data is ordinal.   At best this only captures a relative ranking of
abundance and ordinal ranks are assigned after data collection.    I've
been trying to find a procedure in R that can handle ordinal based
classification and so far have not found one.

Does one exist ?  If there is one, which package supports this type of
analysis and  what is the function ?

Thanks in advance.
Steve




Steve Friedman Ph. D.
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

______________________________________________
R-help at 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.

Thanks Phil,

I'll do so now.

Much appreciated.

Steve

Steve Friedman Ph. D.
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


                                                                           
             Phil Spector                                                  
             <spector at stat.ber                                             
             keley.edu>                                                 To 
                                       Steve_Friedman at nps.gov              
             10/19/2010 02:23                                           cc 
             PM                        r-help at r-project.org                
                                                                   Subject 
                                       Re: [R] Clustering with ordinal     
                                       data                                
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           




Steve -
    Take a look at daisy() in the cluster package.

                                                             - Phil Spector
                                                              Statistical
Computing Facility
                                                              Department of
Statistics
                                                              UC Berkeley

spector at stat.berkeley.edu

Hello

I've been asked to help evaluate a vegetation data set, specifically to
examine it for community similarity. The initial problem I see is that

the

data is ordinal.   At best this only captures a relative ranking of
abundance and ordinal ranks are assigned after data collection.    I've
been trying to find a procedure in R that can handle ordinal based
classification and so far have not found one.

Does one exist ?  If there is one, which package supports this type of
analysis and  what is the function ?

Thanks in advance.
Steve




Steve Friedman Ph. D.
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

______________________________________________
R-help at 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.

Hello Steve,

I've been asked to help evaluate a vegetation data set, specifically to
examine it for community similarity. The initial problem I see is that the
data is ordinal. ? At best this only captures a relative ranking of
abundance and ordinal ranks are assigned after data collection.

Just about every vegetation survey ever conducted uses either presence
absence or ordinal data collection (e.g. Braun-Blanquet scores or
importance scores from nested quadrats).

A large number of distance metrics are in the literature to deal with
such data. As well as Phil's suggestion you should definitely look at
the vegan package which contains a good selection of these metrics
plus numerous functions frequently used in classification and
ordination of veg data.

Michael

Hello

I've been asked to help evaluate a vegetation data set, specifically to
examine it for community similarity. The initial problem I see is that the
data is ordinal. ? At best this only captures a relative ranking of
abundance and ordinal ranks are assigned after data collection. ? ?I've
been trying to find a procedure in R that can handle ordinal based
classification and so far have not found one.

Does one exist ? ?If there is one, which package supports this type of
analysis and ?what is the function ?

Thanks in advance.
Steve




Steve Friedman Ph. D.
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

______________________________________________
R-help at 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.