lv3                 package:simecol                 R Documentation

_L_o_t_k_a-_V_o_l_t_e_r_r_a-_T_y_p_e _M_o_d_e_l _w_i_t_h _R_e_s_o_u_r_c_e, _P_r_e_y _a_n_d _P_r_e_d_a_t_o_r

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

     'simecol' example: predator prey-model with three equations:
     predator, prey and resource (e.g. nutriens, grassland).

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

     data(lv3)

_F_o_r_m_a_t:

     A valid S4 object according to the 'odeModel' specification.  The
     object contains the following slots:

     '_m_a_i_n' Lotka-Volterra equations for predator prey and resource.

     '_p_a_r_m_s' Vector with named parameters of the model:

          '_c' growth rate of the prey population,

          '_d' encounter rate of predator and prey,

          '_e' yield factor (allows conversion with respect to 'd'),

          '_f' death rate of the predator population,

          '_g' recycling parameter.


     '_i_n_p_u_t_s' Time series specifying external delivery of resource.

     '_t_i_m_e_s' Simulation time and integration interval.

     '_i_n_i_t' Vector with start values for 's', 'p' and 'k'.

          '_s' Resource (e.g. grassland or phosphorus).

          '_p' Producer (prey).

          '_k' Consumer (predator).


     '_s_o_l_v_e_r' Character string specifying the integration method.

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

     'simecol-package', 'sim', 'parms', 'init', 'times'.

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

         data(lv3)
         plot(sim(lv3))
         solver(lv3) <- "lsoda"
         plot(sim(lv3))         # wrong! automatic time step overlooks internal inputs
         plot(sim(lv3, hmax=1)) # integration with correct maximum time step

