validity                package:clue                R Documentation

_V_a_l_i_d_i_t_y _M_e_a_s_u_r_e_s _f_o_r _P_a_r_t_i_t_i_o_n_s _a_n_d _H_i_e_r_a_r_c_h_i_e_s

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

     Compute validity measures for partitions and hierarchies,
     attempting to measure how well these clusterings capture the
     underlying structure in the data they were obtained from.

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

     cl_validity(x, ...)
     ## Default S3 method:
     cl_validity(x, d, ...)

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

       x: an object representing a partition or hierarchy.

       d: a dissimilarity object from which 'x' was obtained.

     ...: arguments to be passed to or from methods.

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

     'cl_validity' is a generic function.

     For partitions, its default method gives the "dissimilarity
     accounted for", defined as

        sum_{i,j} sum_k m_{ik}m_{jk} d_{ij} / sum_{i,j} d_{ij}

     where d and m are the dissimilarities and memberships,
     respectively, and the sum is over all pairs of objects and all
     classes.

     For hierarchies, currently no validity measures are computed by
     default.  For the results of using 'agnes' and 'diana', the
     agglomerative and divisive coefficients are provided.

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

     A list of class '"cl_validity"' with the computed validity
     measures.

_S_e_e _A_l_s_o:

     'cluster.stats' in package 'fpc' for a variety of cluster
     validation statistics; 'fclustIndex' in package 'e1071' for
     several fuzzy cluster indexes; 'clustIndex' in package 'cclust';
     'silhouette' in package 'cluster'.

