make.link               package:stats               R Documentation

_C_r_e_a_t_e _a _L_i_n_k _f_o_r _G_L_M _f_a_m_i_l_i_e_s

_D_e_s_c_r_i_p_t_i_o_n:

     This function is used with the 'family' functions in 'glm()'.
     Given a link, it returns a link function, an inverse link
     function, the derivative dmu/deta and a function for domain
     checking.

_U_s_a_g_e:

     make.link(link)

_A_r_g_u_m_e_n_t_s:

    link: character or numeric; one of '"logit"', '"probit"',
          '"cloglog"', '"identity"', '"log"',  '"sqrt"',  '"1/mu^2"',
          '"inverse"', or number, say lambda resulting in power link mu
          ^ lambda.

_V_a_l_u_e:

     A list with components 

 linkfun: Link function 'function(mu)'

 linkinv: Inverse link function 'function(eta)'

  mu.eta: Derivative 'function(eta)' dmu/deta

valideta: 'function(eta)'{ 'TRUE' if all of 'eta' is in the domain of
          'linkinv' }.

_S_e_e _A_l_s_o:

     'glm', 'family'.

_E_x_a_m_p_l_e_s:

     str(make.link("logit"))

     l2 <- make.link(2)
     l2$linkfun(0:3)# 0 1 4 9
     l2$mu.eta(eta= 1:2)#= 1/(2*sqrt(eta))

