MDS and Cluster Analysis Examples
Michael Friendly 
Psychology 6140
 
 
 SAS Sample Library
The programs below are distributed with SAS (Ver 6.08 and later)
and are stored in the directory !sasroot\stat\samples. 
 
 
- mdsauto sas  
- Similarities of automobiles with confidence ratings.
        10 Subjects rated the similarity of pairs of 20 automobiles,
        and gave confidence judments in their ratings.  An initial
        unweighted analysis is followed by one in which the confidence
        judgments are used as weights in the MDS analysis.
- mdscity sas   
- Intercity flying distances: Ordinal, interval &
			ratio MDS analysis with good and bad starting
			configurations.
- mdscola sas   
- Cola experiment: 46 subjects, 6 cola drinks
			rated for similarity in taste and smell. Ordinal &
			interval replicated MDS analysis.
 
- mdsdist sas   
- Computing a distance matrix for 0/1 data.
 
- mdsex sas   
- Examples from the User's Guide.  Includes Jacobowitz body
		parts data for 6 yr olds and
      adults: Nonmetric weiughted INDSCAL
      analysis.
 
- mdsindsp sas 
- MDS plots of group & individual configuration spaces. 
        Using the data on judged similarity of programming languages,
        an INDSCAL model is fit, then the individual subjects' 
        configurations are plotted.
- mdslang sas  
- Similarity of 14 common programming languages
			rated by 10 graduate students: INDSCAL analysis
			plus one MDS analysis for each subject.
- mdsperc sas   
- Intercity distance perception: Judged distances
			among 10 American cities. Asymmetric data, INDSCAL
			analysis.
 
- mdsrank sas   
- Ranked flying distances: Data from MDSCITY
                  converted to ranks, ordinal, interval & ratio MDS
                  analyses with good and bad starting configurations.
 
- mdssoda sas  
- Taste and smell soda experiment.
        Dissimilarity judgments from 46 subjects about 6 sodas,
        ordinal measurement level
- mdsuni sas   
- Perfect unidimensional row-conditional data,
        with missing rows, interval and ordinal analysis.
			Replicated asymmetric analysis.
 
- distance sas  
- A general macro for computing many different types
	of distance/similarity measures.
 
- clustex1 sas  
- Intercity flying distances analyzed by a variety of methods available in Proc CLUSTER.
- clustex2 sas  
- Birth and death rates in countries in 1976 analyzed by a
	variety of methods available in Proc CLUSTER.
- clustex3 sas  
- Fisher's Iris data, Proc CLUSTER and
                  canonical discriminant analysis.
  
PSYCH614 Disk 
 
The programs below are stored in the Psych614 directory,
N:\sasuser\psy6140\examples\cluster.
 
- country.sas   
- Averaged judged similarity of 12 countries.
- helm.sas      
- INDSCAL analysis of Helm's data on color
                  perception in normal and color-blind subjects.
 
- marriage.sas  
- Rates of intermarriage among 8 ethnic groups in
			Hawaii were used by Parkman & Sawyer (1967) to
			define distances among these groups which were
			studied by MDS techniques. This analysis uses an
			INDSCAL model to examine changes over time and
			compares the results with PROC CLUSTER.
 
- mdsauto.sas   
- Shows use of Proc CANCORR to fit the Vector
			Model and Ideal Point Model to relate ratings of
			automobiles on various properties to the MDS space.
 
- mutation.sas  
- Mutation distances among 20 species (Fitch &
			Margoliash data):  MDS compared to CLUSTER 
			procedure.  The mutation distances were
			used by Fitch & Margoliash to derive a phylogenetic
			tree.
 
- similar.sas   
- Constructing a similarity rating form with SAS.
			For the experiment on similarities among
			programming languages in mdslang.sas.
 
- things.sas    
- Distance estimates of 25 natural concepts rated
			by psychology undergraduates and biology graduate
			students (Schvanaveldt data): The items were chosen
			to have both hierarchical and non-hierarchical
			relationships, rather than underlying continuous
			dimensions.