MDS and Cluster Analysis Examples
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
- 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
- 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
- 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.
The programs below are stored in the Psych614 directory,
- Averaged judged similarity of 12 countries.
- INDSCAL analysis of Helm's data on color
perception in normal and color-blind subjects.
- 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.
- 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 distances among 20 species (Fitch &
Margoliash data): MDS compared to CLUSTER
procedure. The mutation distances were
used by Fitch & Margoliash to derive a phylogenetic
- Constructing a similarity rating form with SAS.
For the experiment on similarities among
programming languages in mdslang.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