qrmix (version 0.9.0)

Bisquare: Tukey's Bisquare Loss

Description

"Bisquare" evaluates Tukey's Bisquare function defined as $$ f(r) = \left\{ \begin{array}{ll} 1-(1-(\frac{r}{c})^2)^3) & |r| \le c \\ 1 & |r| > c \end{array} \right. $$

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Usage

Bisquare(r, c = 4.685)

Arguments

r

a real number or vector.

c

a positive number. If the value is negative, it's absolute value will be used.

Examples

set.seed(1)
x = rnorm(200, mean = 3)
y = Bisquare(x)
plot(x, y)