

Double Poisson(rmutil)                       R Documentation

_T_h_e _D_o_u_b_l_e _P_o_i_s_s_o_n _D_i_s_t_r_i_b_u_t_i_o_n

_U_s_a_g_e_:

     ddoublepois(y, m, s)
     pdoublepois(q, m, s)

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

       y: vector of counts

       q: vector of quantiles

       m: vector of means

       s: vector of overdispersion parameters

_V_a_l_u_e_:

     These functions provide information about the double
     Poisson distribution with parameters `m' and `s'.
     `ddoublepois' gives the density and `pdoublepois' gives
     the distribution function.

     The double Poisson distribution with `mu' = m has den-
     sity

       p(y) = c(m,s) s^(y/m) (m/y)^(y log(s)) y^(y-1) / y!

     for y = 0, ..., where c(.) is a normalizing constant.

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

     `dpois' for the Poisson, `dmultpois' for the multi-
     plicative Poisson, and `dnbinom' for the negative bino-
     mial distribution.

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

     ddoublepois(5,5,0.9)
     pdoublepois(5,5,0.9)

