simplex                 package:VGAM                 R Documentation

_S_i_m_p_l_e_x _d_i_s_t_r_i_b_u_t_i_o_n

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

     The two parameters of the univariate simplex distribution are
     estimated.

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

     simplex(lmu = "logit", lsigma = "loge", imu = NULL, isigma = NULL)

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

     lmu: Link function for 'mu'.  See 'Links' for more choices. The
          parameter lies in the unit interval.

  lsigma: Link function for 'sigma'.  See 'Links' for more choices. The
          parameter is positive, therefore the log link is the default.

imu, isigma: Optional initial values for 'mu' and 'sigma'. A 'NULL'
          means a value is obtained internally.

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

     See Jorgensen (1997) for details.

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

     An object of class '"vglmff"' (see 'vglmff-class'). The object is
     used by modelling functions such as 'vglm', and 'vgam'.

_N_o_t_e:

     This distribution is potentially useful for dispersion modelling.
     This family function only works for intercept-only models, i.e.,
     the formula should have '~ 1'.

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

     T. W. Yee

_R_e_f_e_r_e_n_c_e_s:

     Jorgensen, B. (1997) _The Theory of Dispersion Models_. London:
     Chapman & Hall

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

     'rig'.

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

     x = runif(n <- 100)
     y = rbeta(n, shape1=3+x, shape2=4-x)
     fit = vglm(y ~ 1, simplex, trace=TRUE, eps=1e-9, cri="c")
     coef(fit, matrix=TRUE)
     Coef(fit)
     fit
     summary(fit)

