

   cmdscale {mva}                               R Documentation

   CCllaassssiiccaall ((MMeettrriicc)) MMuullttiiddiimmeennssiioonnaall SSccaalliinngg

   DDeessccrriippttiioonn::

        Classical muiltidimensional scaling of a data matrix.

   UUssaaggee::

        cmdscale(d, k = 2, eig = FALSE)

   AArrgguummeennttss::

          d: a distance structure such as that returned by
             `dist' or a full symmetric matrix containing the
             dissimilarities.

          k: the dimension of the space which the data are to
             be represented in.

        eig: indicates whether eigenvalues should be returned.

   DDeettaaiillss::

        Multidimensional scaling takes a set of dissimilarities
        and returns a set of points such that the distances
        between the points are approximately equal to the dis-
        similarities.

        The functions `isoMDS' and `sammon' in package `MASS'
        provide alternative ordination techniques.

   VVaalluuee::

        A list containing the following components.

     points: a matrix with `k' columns whose rows give the
             coordinates of the points chosen to represent the
             dissimilarities.

        eig: if requested, the eigenvalues computed during the
             scaling process.

   NNoottee::

        The S version of this function provides for computing
        an additional ``fiddle'' factor suggested by Torgerson.
        R does not provide this option.

   RReeffeerreenncceess::

        Seber, G. A. F. (1984). Multivariate Analysis. New
        York: Wiley.

        Torgerson, W. S. (1958). Theory and Methods of Scaling.
        New York: Wiley.

   SSeeee AAllssoo::

        `dist'. Also `isoMDS' and `sammon' in package `MASS'.

   EExxaammpplleess::

        data(eurodist)
        loc <- cmdscale(eurodist)
        x <- loc[,1]
        y <- -loc[,2]
        plot(x, y, type="n",
             xlab="", ylab="")
        text(x, y, names(eurodist), cex=0.5)

