| sigmaPA {icesAdvice} | R Documentation |
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)