verhulst                package:pomp                R Documentation

_S_i_m_p_l_e _V_e_r_h_u_l_s_t-_P_e_a_r_l (_l_o_g_i_s_t_i_c) _m_o_d_e_l.

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

     'verhulst' is a 'pomp' object encoding a univariate stochastic
     logistic model with measurement error.

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

     data(verhulst)

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

     The model is written as an Ito diffusion, dn = r n (1-n/K) dt +
     sigma n dW, where W is a Wiener process. It is implemented using
     the 'euler.simulate' plug-in.

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

     'pomp-class' and the vignettes

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

     data(verhulst)
     plot(verhulst)
     coef(verhulst)
     params <- cbind(
                     c(n.0=100,K=10000,r=0.2,sigma=0.4,tau=0.1),
                     c(n.0=1000,K=11000,r=0.1,sigma=0.4,tau=0.1)
                     )
     x <- simulate(verhulst,params=params,states=TRUE)
     matplot(time(verhulst,t0=TRUE),t(x['n',,]),type='l')
     y <- trajectory(verhulst,params=params)
     matlines(time(verhulst,t0=TRUE),t(y['n',,]),type='l',lwd=2)

