Jackknife Estimation

Jackknife Estimation

Usage

# S4 method for class 'DiversityIndex'
jackknife(object, f = NULL)

Arguments

object

An R object (typically a DiversityIndex object).

f

A function that takes a single numeric vector (the leave-one-out values) as argument.

Value

If f is NULL (the default), jackknife() returns a numeric matrix with the following columns:

original

The observed value.

mean

The jackknife estimate of mean.

bias

The jackknife estimate of bias.

error

The jackknife estimate of standard error.

If f is a function, jackknife() returns the result of f applied to the leave-one-out values.

See also

Other resampling methods: bootstrap()

Author

N. Frerebeau

Examples

## Data from Conkey 1980, Kintigh 1989
data("cantabria")

## Shannon diversity index
(h <- heterogeneity(cantabria, method = "shannon"))
#> [1] 3.269200 2.955298 2.491683 2.485604 2.329187

## Jackknife resampling
jackknife(h)
#>                  original     mean       bias      error
#> Altamira         3.269200 3.246457 -0.9779158 0.08145529
#> Cueto de la Mina 2.955298 2.932856 -0.9649994 0.15907033
#> El Juyo          2.491683 2.469588 -0.9500688 0.19670002
#> El Cierro        2.485604 2.462723 -0.9838709 0.22195573
#> La Paloma        2.329187 2.305876 -1.0023704 0.25266291

jackknife(h, f = summary)
#>                      Min.  1st Qu.   Median     Mean  3rd Qu.     Max.
#> Altamira         3.230811 3.236056 3.249552 3.246457 3.250979 3.269684
#> Cueto de la Mina 2.902193 2.911984 2.921893 2.932856 2.955298 3.018158
#> El Juyo          2.410614 2.444200 2.491683 2.469588 2.491683 2.529489
#> El Cierro        2.398698 2.425153 2.485604 2.462723 2.485604 2.485604
#> La Paloma        2.227438 2.260234 2.329187 2.305876 2.329187 2.329187