psiFunc              package:robustbase              R Documentation

_C_o_n_s_t_r_u_c_t_o_r _f_o_r _O_b_j_e_c_t_s "_P_s_i _F_u_n_c_t_i_o_n" _C_l_a_s_s

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

     'psiFunc(..)' is a convenience interface to 'new("psi_func",..)',
     i.e. for constructing objects of class '"psi_func"'.

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

     psiFunc(rho, psi, wgt, Dpsi, Erho = NULL, Epsi2 = NULL, EDpsi = NULL, ...)

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

rho, psi, wgt, Dpsi: each a 'function' of 'x' and tuning parameters
          typically.

Erho, Epsi2, EDpsi: see 'psi_func-class', and note that these may
          change in the future.

     ...: potential further arguments for specifying tuning parameter
          names and defaults.

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

     Martin Maechler

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

     'psi_func-class' for the class description.

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

     ## classical {trivial, not interesting}:
     F1 <- function(x) rep.int(1, length(x))
     cPsi <- psiFunc(rho = function(x) x^2 / 2, psi = function(x) x,
                     wgt = F1, Dpsi = F1,
                     Erho = function(x) rep.int(1/2, length(x)),
                     Epsi2 = F1, EDpsi = F1)

