[comp.graphics.visualization] Chernoff's Faces

khannara@cs.umr.edu (Rashi Khanna) (01/08/91)

Hi!

Has anyone worked with FACES (Chernoff)? It is one of the techniques
of representing multivariate data and is often used in statistical analysis.
I would like to know more about the graphical implementation of FACES.

If someone has any knowledge of this, could you please send a reply 
at khannara@cs.umr.edu.

Thanks,
Rashi.

metz@bolek.iam.unibe.ch (Igor Metz) (01/09/91)

If you are interested in Flury/Riedwyl faces, which are an extension of
Chernoff faces, then I can help you. This extension has been developped
in the Statistics Dept. of our University. A first implementation has been
written in Fortran for IBM/MVS (output on Calcomp plotter) [by Bernie Flury].
A newer version is available for MS-DOS (in Turbo Pascal 3 and in BASIC) [written
by Michel Schuepbach].
Let me know if you are interested.
-- 
Igor Metz
Institut fuer Informatik und angew. Mathematik, Universitaet Bern, Switzerland.
domainNet: metz@iam.unibe.ch               Phone: (0041) 31 65 49 90
ARPA:      metz%iam.unibe.ch@relay.cs.net  Fax:   (0041) 31 65 39 65

eugene@eos.arc.nasa.gov (Eugene Miya) (01/10/91)

As was pointed out to me, Rick Becker's S stat package has them.
Here's the help command on it.  See the book for the graphic
examples.  I recommend the paper reference.

--e.n. miya, NASA Ames Research Center, eugene@eos.arc.nasa.gov
  {uunet,mailrus,most gateways}!ames!eugene
  AMERICA: CHANGE IT OR LOSE IT.
> help("faces")

faces: Plot Symbolic Faces

faces(x, which, labels, head, max, nrow, ncol, fill, scale, byrow)

ARGUMENTS:
x:     matrix of data values.
which: the columns of `x' to be used as the first, second, etc. parameter in the

       symbolic face. Default `1:min(15,ncol(x))'. See NOTE below for meaning of

       parameters.
labels:optional character vector of labels for the faces (i.e., for the rows of
       `x').
head:  optional character vector to use as the heading for the plot.
max:   a suggested value for the number of rows and columns to go on each page.
       By default, all the faces will be fitted onto one page.
nrow:
ncol:  optionally, may be given to specify exactly the number of rows and
       columns for the array of plots on each page.
fill:  if TRUE (the default), all unused parameters of the face will be set to
       their nominal (midpoint) value. If FALSE, all features corresponding to
       unused parameters will not be plotted.
scale: if TRUE (the default), the columns of `x' will be independently scaled to

       (0,1). If FALSE no scaling will be done. The data values should then be
       scaled to the same overall range by some other means; e.g., by scaling
       the whole of `x' to the range (0,1).
byrow: if TRUE, plots produced in row-wise order; if FALSE (the default) plots
       are produced in column-wise order.

NOTE:  the feature parameters are: 1-area of face; 2-shape of face; 3-length of
       nose; 4-loc. of mouth; 5-curve of smile; 6-width of mouth;
       7,8,9,10,11-loc., separation, angle, shape and width of eyes; 12-loc. of
       pupil; 13,14,15-loc., angle and width of eyebrow.

REFERENCE
H. Chernoff, "The use of Faces to Represent Points in k-Dimensional Space
Graphically", Journal of the American Statistical Association, Vol. 68, pp
361-368, 1973.

EXAMPLES:
        faces(chernoff2,head="Chernoff's Second Example")