sigmaPA: Sigma from PA Reference Points

In arnima-github/icesAdvice: Functions Related to ICES Advice

Sigma from PA Reference Points

Description

Calculate the implicit sigma that was used to calculate PA reference points from limit reference points (Xpa from Xlim).

Usage

sigmaPA(lim, pa)

Arguments

lim	the value of the limit reference point, e.g., Blim or Flim.
pa	the value of the PA reference point, e.g., Bpa or Fpa.

Details

The order of the parameters does not matter, so sigmaPA(Fpa, Flim) and sigmaPA(Flim, Fpa) are equivalent.

Value

Implicit value of sigma.

Note

The purpose of PA reference points is to apply a precautionary approach in fisheries management.

This function is useful for reviewing PA reference points, when the advice sheet provides the value of Xlim and Xpa but not the value of sigma.

The inference is based on the following relationships:

B_\mathrm{pa} = B_\mathrm{lim} \exp(1.645\sigma_B)

F_\mathrm{pa} = F_\mathrm{lim} \exp(-1.645\sigma_F)

Author(s)

Arni Magnusson.

See Also

sigmaCI calculates the implicit sigma from a confidence interval.

Bpa and Fpa calculate those reference points from the limit reference points, based on a given sigma.

icesAdvice-package gives an overview of the package.

Examples

sigmaPA(100, 120)

arnima-github/icesAdvice documentation built on Oct. 28, 2023, 10:19 a.m.