M-estimators {metRology}

M- and MM-estimators for location.

Description

Functions for calculating M- and MM-estimators for location given values and associated standard errors or standard uncertainties.

Usage

MM.estimate(x, ...)

## Default S3 method:
MM.estimate(x, u, c = 4.685, ...)

huber.estimate(x, ...)

## Default S3 method:
huber.estimate(x, u, k= 1.345, ...)

Arguments

x

numeric vector of mean values for groups

u

numeric vector of standard deviations or standard uncertainties associated with the values x

c, k

Tuning parameters passed to other functions (see rlm)

...

Parameters passed to other functions.

Details

These functions are wrappers for robust estimation using rlm. All simply call rlm with the formula x~1 and weights 1/u^2.

Value

An object of class ‘loc.est’.

Author(s)

S. L. R. Ellison [e-mail]

References

None, yet.

See Also

rlm, loc.est-class

Examples

## Cd heat of vapourisation example 
## from Paule, R. C.  and Mandel, J. (1982) - see ?mpaule
x2<-c(27.044, 26.022, 26.340, 26.787, 26.796)
v<-c(3, 76, 464, 3, 14)*1e-3

MM.estimate(x2, sqrt(v))

huber.estimate(x2, sqrt(v))