mcp                package:adehabitat                R Documentation

_E_s_t_i_m_a_t_i_o_n _o_f _t_h_e _H_o_m_e _R_a_n_g_e _U_s_i_n_g _t_h_e _M_i_n_i_m_u_m _C_o_n_v_e_x _P_o_l_y_g_o_n
_E_s_t_i_m_a_t_o_r

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

     'mcp' computes the home range of several animals using the minimum
     convex polygon estimator.
      'mcp.area' is used for home-range size estimation.  This function
     requires the package 'gpclib'.
      'plot.hrsize' is used to display the home-range size estimated at
     various levels.

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

     mcp(xy, id, percent = 95)
     mcp.area(xy, id, percent = seq(20,95, by=5),
              unin = c("m", "km"),
              unout = c("ha", "km2", "m2"))
     plot.hrsize(x, ...)

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

      xy: a data frame containing the coordinates of the relocation of
          the monitored animals

      id: a factor giving the identity of the animal for each
          relocation

 percent: 100 minus the proportion of outliers to be excluded from the
          computation 

    unin: the units of the relocations coordinates.  Either '"m"'
          (default) for meters or '"km"' for kilometers

   unout: the units of the output areas.  Either '"m2"' for square
          meters, '"km2"' for square kilometers or '"ha"' for hectares
          (default)

       x: an objet of class 'hrsize' returned by the function
          'mcp.area', or 'kernel.area' (see the help page of this
          function)

     ...: additionnal arguments to be passed to the function 'plot'

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

     This function computes the Minimum Convex Polygon estimation after
     the removal of '(100 minus percent)' percent of the relocations
     the farthest away from the barycenter of the home range (computed
     by the arithmetic mean of the coordinates of the relocations for
     each animal).

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

     'mcp' returns an object of class 'area', with one polygon per
     level of the factor ID.
      'mcp.area' returns a data frame of class 'hrsize',  with one
     column per animal and one row per level of estimation of the home
     range

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

     Clment Calenge calenge@biomserv.univ-lyon1.fr

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

     Mohr, C.O. (1947) Table of equivalent populations of north
     american small mammals. _The American Midland Naturalist_, *37*,
     223-249.

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

     'chull', 'plot.area' to have a graphical display of the home
     ranges, 'as.area' for additionnal information on the class 'area',
     and 'area2dxf' for further exportation toward a GIS. 's.chull' for
     another way to display MCP

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

     data(puechabon)
     locs <-  puechabon$locs

     cp <- mcp(locs[,4:5], locs[,1])

     ## Plot the home ranges
     opar <- par(mar = c(0,0,0,0))
     area.plot(cp)

     ## ... And the relocations
     points(locs[,4:5], pch = 16, col = as.numeric(locs[,1]))
     par(opar)

     ## Computation of the home-range size:
     if (require(gpclib)) {
       (cuicui1 <- mcp.area(locs[,4:5], locs[,1]))
       plot(cuicui1)
     }

