loc_est: The location estimate class
In metRology: Support for Metrological Applications

Description Usage Arguments Details Value Author(s) References See Also Examples

The location estimate class contains output from a variety of estimators used in the metRology package.

A print method is provided.

1 2	## S3 method for class 'loc.est' print(x, ...)

`x`	An object of class ‘loc.est’
`...`	Parameters passed to other functions. Currently unused.

An object of class ‘loc.est’ is a list containing

x: Scalar estimate of location
u: Standard uncertainty (usually equivalent to standard error) of the location estimate.
df: Degrees of freedom associated with the location estimate (may be NA)
xi: Numeric vector of individual values contributing to the estimate
ui: Numeric vector of uncertainties initially associated with xi.
dfi: Numeric vector of degrees of freedom associated with ui.
u.eff: Numeric vector of ‘effective uncertainties’ in xi after any additional terms or adjustments are added (see below).
w: Numeric vector of weights associated with xi (see below).
method: Character string describing the method used to obtain the estimate.
method.details: An optional list of additional details provided by the particular method used.

The ‘effective uncertainties’ u.eff arise from some estimation methods (for example, Mandel-Paule). These typically involve either the estimation of an additional variance term, a scale adjustment to the output value uncertainty or (for example in the case of the arithmetic mean) replacement of the initial individual uncertainties with some single estimate based on the dispersion of values. These adjustments are usually equivalent to replacing the estimator used with a weighted mean using weights 1/u.eff^2.

The weight vector w is not equivalent to 1/u.eff^2. Rather, it gives the ratio of prior weights 1/u.eff^2 to posterior weights, which combine prior weights with some additional weighting. Posterior weights arise in particular when using robust estimators, and are generally 1 otherwise. The returned location estimate in such cases can be calculated as sum(w*x/(u^2))/sum(w/(u^2))).

method.details is an optional list that may contain anything from a short summary of a scale factor or additional variance to a complete object (e.g. an rlm object) returned by the function used to calculate the estimate.

The print method is called for its side effect; no value is returned.

S. L. R. Ellison s.ellison@lgc.co.uk

None, yet

mpaule

## Cd heat of vapourisation example (see ?mpaule)
x2<-c(27.044, 26.022, 26.340, 26.787, 26.796)
v<-c(3, 76, 464, 3, 14)*1e-3
mp<-mpaule(x2, sqrt(v))

print(mp)