incmatrix              package:prabclus              R Documentation

_N_e_s_t_e_d_n_e_s_s _m_a_t_r_i_x

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

     Computes species*species nestedness matrix and number of nestings
     (inclusions) from regions*species presence-absence matrix.

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

     incmatrix(regmat)

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

  regmat: 0-1-matrix. Columns are species, rows are regions.

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

     A list with components 

       m: 0-1-matrix. 'm[i,j]=1' means that the occupied region of
          species j is a subset (or equal) of the region of species i.

    ninc: integer. Number of strict inclusions.

     neq: integer. Number of region equalities between species (not
          including equality between species i and i).

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

     Christian Hennig hennig@math.uni-hamburg.de <URL:
     http://www.math.uni-hamburg.de/home/hennig/>

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

     Hausdorf, B. and Hennig, C. (2003) Nestedness of nerth-west
     European land snail ranges as a consequence of differential
     immigration from Pleistocene glacial refuges. _Oecologia_ 135,
     102-109.

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

     'prabtest'

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

     data(kykladspecreg)
     # Note: If you do not use the installed package, replace this by
     # kykladspecreg <- read.table("(path/)kykladspecreg.dat")
     incmatrix(t(kykladspecreg))$ninc

