disana                package:labdsv                R Documentation

_D_i_s_s_i_m_i_l_a_r_i_t_y _A_n_a_l_y_s_i_s

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

     Dissimilarity analysis is a graphical analysis of the distribution
     of values in a dissimilarity matrix

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

     disana(x)

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

       x: an object of class 'dist' such as returned by 'dist',
          'vegdist' or 'dsvdis'

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

     Calculates three vectors: the minimum, mean, and maximum
     dissimilarity for each sample in a dissimilarity matrix. By
     default it produces three plots: the sorted dissimilarity values,
     the sorted min, mean, and maximum dissimilarity for each sample,
     and the mean dissimilarity versus the minimum dissimilarity for
     each sample. Optionally, you can identify sample plots in the last
     panel with the mouse.

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

     Plots three graphs to the current graphical device, and returns an
     (invisible) list with four components: 

     min: the minimum dissimilarity of each sample to all others

    mean: the mean dissimilarity of each sample to all others

     max: the maximum dissimilarity of each sample to all others

   plots: a vector of samples identified in the last panel

_N_o_t_e:

     Dissimilarity matrices are often large, and difficult to visualize
     directly.  'disana' is designed to highlight aspects of interest
     in these large matrices.  If the first panel shows a long limb of
     constant maximum value, you should consider recalculating the
     dissimilarity with a step-across adjustment. The third panel is
     useful for identifying outliers, which are plots more than 0.5
     dissimilar to their nearest neighbor.

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

     David W. Roberts droberts@montana.edu

_R_e_f_e_r_e_n_c_e_s:

     <URL: http://ecology.msu.montana.edu/labdsv/R/labdsv>

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

         data(bryceveg) # returns a data.frame called veg
         dis.bc <- dsvdis(bryceveg,'bray/curtis')
         disana(dis.bc)

