layout.drl              package:igraph              R Documentation

_T_h_e _D_r_L _g_r_a_p_h _l_a_y_o_u_t _g_e_n_e_r_a_t_o_r

_D_e_s_c_r_i_p_t_i_o_n:

     DrL is a force-directed graph layout toolbox focused on real-world
     large-scale graphs, developed by Shawn Martin and colleagues at
     Sandia National Laboratories.

_U_s_a_g_e:

     layout.drl (graph, use.seed = FALSE, seed = matrix(runif(vcount(graph) * 
         2), nc = 2), options = igraph.drl.default, weights = E(graph)$weight, 
         fixed = NULL, dim = 2) 

_A_r_g_u_m_e_n_t_s:

   graph: The input graph, in can be directed or undirected.

use.seed: Logical scalar, whether to use the coordinates given in the
          'seed' argument as a starting point.

    seed: A matrix with two columns, the starting coordinates for the
          vertices is 'use.seed' is 'TRUE'. It is ignored otherwise.

 options: Options for the layout generator, a named list. See details
          below.

 weights: Optional edge weights. Supply 'NULL' here if you want to
          weight edges equally. By default the 'weight' edge attribute
          is used if the graph has one.

   fixed: Logical vector, it can be used to fix some vertices. All
          vertices for which it is 'TRUE' are kept at the coordinates
          supplied in the 'seed' matrix. It is ignored it 'NULL' or if
          'use.seed' is 'FALSE'. 

     dim: Either '2' or '3', it specifies whether we want a two
          dimensional or a three dimensional layout. Note that because
          of the nature of the DrL algorithm, the three dimensional
          layout takes significantly longer to compute.

_D_e_t_a_i_l_s:

     This function implements the force-directed DrL layout generator.

     The generator has the following parameters:

   _e_d_g_e._c_u_t Edge cutting is done in the late stages of the algorithm in
        order to achieve less dense layouts.  Edges are cut if there is
        a lot of stress on them (a large value in the objective
        function sum). The edge cutting parameter is a value between 0
        and 1 with 0 representing no edge cutting and 1 representing
        maximal edge cutting.  

   _i_n_i_t._i_t_e_r_a_t_i_o_n_s Number of iterations in the first phase.

   _i_n_i_t._t_e_m_p_e_r_a_t_u_r_e Start temperature, first phase.

   _i_n_i_t._a_t_t_r_a_c_t_i_o_n Attraction, first phase.

   _i_n_i_t._d_a_m_p_i_n_g._m_u_l_t Damping, first phase.

   _l_i_q_u_i_d._i_t_e_r_a_t_i_o_n_s Number of iterations, liquid phase.

   _l_i_q_u_i_d._t_e_m_p_e_r_a_t_u_r_e Start temperature, liquid phase.

   _l_i_q_u_i_d._a_t_t_r_a_c_t_i_o_n Attraction, liquid phase.

   _l_i_q_u_i_d._d_a_m_p_i_n_g._m_u_l_t Damping, liquid phase.

   _e_x_p_a_n_s_i_o_n._i_t_e_r_a_t_i_o_n_s Number of iterations, expansion phase.

   _e_x_p_a_n_s_i_o_n._t_e_m_p_e_r_a_t_u_r_e Start temperature, expansion phase.

   _e_x_p_a_n_s_i_o_n._a_t_t_r_a_c_t_i_o_n Attraction, expansion phase.

   _e_x_p_a_n_s_i_o_n._d_a_m_p_i_n_g._m_u_l_t Damping, expansion phase.

   _c_o_o_l_d_o_w_n._i_t_e_r_a_t_i_o_n_s Number of iterations, cooldown phase.

   _c_o_o_l_d_o_w_n._t_e_m_p_e_r_a_t_u_r_e Start temperature, cooldown phase.

   _c_o_o_l_d_o_w_n._a_t_t_r_a_c_t_i_o_n Attraction, cooldown phase.

   _c_o_o_l_d_o_w_n._d_a_m_p_i_n_g._m_u_l_t Damping, cooldown phase.

   _c_r_u_n_c_h._i_t_e_r_a_t_i_o_n_s Number of iterations, crunch phase.

   _c_r_u_n_c_h._t_e_m_p_e_r_a_t_u_r_e Start temperature, crunch phase.

   _c_r_u_n_c_h._a_t_t_r_a_c_t_i_o_n Attraction, crunch phase.

   _c_r_u_n_c_h._d_a_m_p_i_n_g._m_u_l_t Damping, crunch phase.

   _s_i_m_m_e_r._i_t_e_r_a_t_i_o_n_s Number of iterations, simmer phase.

   _s_i_m_m_e_r._t_e_m_p_e_r_a_t_u_r_e Start temperature, simmer phase.

   _s_i_m_m_e_r._a_t_t_r_a_c_t_i_o_n Attraction, simmer phase.

   _s_i_m_m_e_r._d_a_m_p_i_n_g._m_u_l_t Damping, simmer phase.

        There are five pre-defined parameter settings as well, these
        are called 'igraph.drl.default', 'igraph.drl.coarsen',
        'igraph.drl.coarsest', 'igraph.drl.refine' and
        'igraph.drl.final'.

_V_a_l_u_e:

     A numeric matrix with two columns.

_A_u_t_h_o_r(_s):

     Shawn Martin google@for.it and Gabor Csardi csardi@rmki.kfki.hu
     for the R/igraph interface and the three dimensional version.

_R_e_f_e_r_e_n_c_e_s:

     <URL: http://www.cs.sandia.gov/~smartin/software.html>

_S_e_e _A_l_s_o:

     'layout' for other layout generators.

_E_x_a_m_p_l_e_s:

     g <- as.undirected(ba.game(100, m=1))
     l <- layout.drl(g, options=list(simmer.attraction=0))
     ## Not run: 
     plot(g, layout=l, vertex.size=3, vertex.label=NA)
     ## End(Not run)

