psi_func-class {robustbase} | R Documentation |
The class "psi_func"
is used to store psi
functions for M-estimation. In particular, an object of the class
contains rho(x), its derivative
psi(x), the weight function psi(x)/x, and
first derivative of psi, Dpsi =
psi'(x).
Objects can be created by calls of the form new("psi_func", ...)
,
but preferably by psiFunc(...)
.
rho
:"functionX"
. This is used to formulate the
objective function; rho() can be regarded as generalized
negative log-likelihood.psi
:"functionX"
.wgt
:"functionX"
.Dpsi
:"functionX"
.tDefs
:Erho
:"functionXal"
~~ Epsi2
:"functionXal"
~~ EDpsi
:"functionXal"
~~ xtras
:
No methods defined with class "psi_func"
in the signature.
Martin Maechler
str(huberPsi, give.attr = FALSE)