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Formula: F = (1 - eps) Phi + eps H

Usage

Contam(epsilon, H, x = NULL)

Arguments

epsilon

Contamination fraction in [0, 1).

H

Sample from the contaminating distribution, used as its empirical distribution function.

x

Points at which the mixture cdf is evaluated, or NULL for -3, -2, ..., 3.

Value

List with estimate (Huber k), k, F, mean, var, eps, n_H, method.

Details

The gross-error model: a fraction eps of the data comes from an arbitrary H instead of the nominal normal. The least favourable member of this neighbourhood has a density normal in the middle and exponential in the tails, whose score is Huber's psi clipped at k, where k solves 2 phi(k)/k - 2 Phi(-k) = eps/(1-eps). That k is reported alongside the mixture itself.

References

Huber (1964), Ann. Math. Statist. 35(1):73-101.

Examples

set.seed(1)
r <- Contam(epsilon = 0.5, H = rnorm(10)); TRUE
#> [1] TRUE