rFace                  package:fpc                  R Documentation

"_F_a_c_e-_s_h_a_p_e_d" _c_l_u_s_t_e_r_e_d _b_e_n_c_h_m_a_r_k _d_a_t_a_s_e_t_s

_D_e_s_c_r_i_p_t_i_o_n:

     Generates "face-shaped" clustered benchmark datasets.

_U_s_a_g_e:

     rFace(n, p = 6, nrep.top = 2, smile.coef = 0.6, dMoNo = 1.2, dNoEy = 1)

_A_r_g_u_m_e_n_t_s:

       n: integer greater or equal to 10. Number of points.

       p: integer greater or equal to 2. Dimension.

nrep.top: integer. Number of repetitions of the hair-top point.

smile.coef: numeric. Coefficient for quadratic term used for generation
          of mouth-points. Positive values=>smile.

   dMoNo: number. Distance from mouth to nose.

   dNoEy: number. Minimum vertical distance from mouth to eyes.

_D_e_t_a_i_l_s:

     The function generates a nice benchmark example for cluster
     analysis.  There are six "clusters" in this data, of which the
     first five are clearly homogeneous patterns, but with different
     distributional shapes and different qualities of separation. The
     clusters are distinguished only in the first two dimensions. The
     attribute 'grouping' is a factor giving the cluster numbers, see
     below. The sixth group of points corresponds to some hairs, and is
     rather a collection of outliers than a cluster in itself. This
     group contains 'nrep.top+2' points. Of the remaining points, 20%
     belong to cluster 1, the chin (quadratic function plus noise). 10%
     belong to cluster 2, the right eye (Gaussian). 30% belong to
     cluster 3, the mouth (Gaussian/squared Gaussian).  20% belong to
     cluster 4, the nose (Gaussian/gamma), and 20% belong to cluster 5,
     the left eye (uniform).

     The distributions of the further variables are homogeneous over
     all points. The third dimension is exponentially distributed, the
     fourth dimension is Cauchy distributed, all further distributions
     are Gaussian.

     Please consider the source code for exact generation of the
     clusters.

_V_a_l_u_e:

     An 'n' times 'p' numeric matrix with attributes 

grouping: a factor giving the cluster memberships of the points.

indexlist: a list of six vectors containing the indices of points
          belonging to the six groups.

_A_u_t_h_o_r(_s):

     Martin Maechler maechler@stat.math.ethz.ch <URL:
     http://stat.ethz.ch/~maechler/>

     Christian Hennig chrish@stats.ucl.ac.uk <URL:
     http://www.homepages.ucl.ac.uk/~ucakche/>

_E_x_a_m_p_l_e_s:

       set.seed(4634)
       face <- rFace(600,dMoNo=2,dNoEy=0)
       grface <- as.integer(attr(face,"grouping"))
       plot(face, col = grface)
       pairs(face, col = grface, main ="rFace(600,dMoNo=2,dNoEy=0)")

