ascgen              package:adehabitat              R Documentation

_C_r_e_a_t_i_o_n _o_f _R_a_s_t_e_r _M_a_p_s

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

     'ascgen' creates an object of class 'asc' using a set of points.

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

     ascgen(xy = NULL, cellsize = NULL, nrcol = 10, count = TRUE)

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

      xy: a data frame with two columns: the x and y coordinates of the
          points

cellsize: the 'cellsize' attribute of the object of class 'asc' to be
          created

   nrcol: the size of the square raster map to be created (number of
          rows and columns)

   count: logical.  If 'TRUE', the object of class 'asc' contains the
          number of points in each cell.  If 'FALSE', all the cells are
          set to zero

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

     Returns an object of class 'asc'.

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

     Clment Calenge calenge@biomserv.univ-lyon1.fr

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

     'import.asc' for additional information on objects of class 'asc'.

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

     data(puechabon)
     lo <- puechabon$locs[,c("X","Y")]
     plot(lo, asp = 1, pch = 16)

     ## lo contains the relocations of wild boars
     rast <- ascgen(lo, cellsize = 100)
     image(rast)

     ## Alternatively, one can specify the size of the square raster map
     rast <- ascgen(lo, nrcol = 10)
     rast
     image(rast)

     ## can be used for further analyses
     ## (e.g. correspondence analyses)
     locs <- puechabon$locs[, c("Name", "X", "Y")]
     o <- count.points.id(locs[,2:3], locs[,1], rast)
     image(o)

