rhoprime2: The second derivative of the rho function

In msalibian/RobStatTM: Robust Statistics: Theory and Methods

The second derivative of the rho function

Description

The second derivative of the rho function

Usage

rhoprime2(u, family, cc, standardize = FALSE)

Arguments

u	point or vector at which rho is to be evaluated
family	family string specifying the name of the family of loss function to be used (current valid options are "bisquare", "opt" and "mopt").
cc	tuning parameters to be computed according to efficiency and / or breakdown considerations. See lmrobdet.control, bisquare, mopt and opt.
standardize	logical value determining whether the rho function is to be standardized so that its maximum value is 1. See Mpsi.

Value

The value of the second derivative of rho evaluated at u

Author(s)

Matias Salibian-Barrera, [e-mail]

Examples

# Evaluate the 2nd derivative of a rho function tuned for 85% efficiency
rhoprime2(u=1.1, family='bisquare', cc=bisquare(.85))
# Evaluate the 2nd derivative of a rho function tuned for 50% breakdown
rhoprime2(u=1.1, family='opt', cc=lmrobdet.control(bb=.5, family='opt')$tuning.chi)

msalibian/RobStatTM documentation built on June 13, 2025, 12:45 p.m.