saturation {EcoTroph}R Documentation

Sigma Saturation Function

Description

This function enables an other calculation for the sigma of the create.smooth function. Sigma is calculated on the base of a saturation function reflecting a biological reasoning about the variability of the TL within the trophic classes: The variability increases with the TL and reaches a plateau after a certain TL.

Usage

saturation(sigma_inf = NULL, coeff = NULL, pas = NULL)

Arguments

sigma_inf defines the value of the curve's plateau.
coeff defines the value of the slope.
pas defines the splitting of the TL classes.

Details

By default sigma is calculated using a lognormal function. This function enables an other user choice reflecting a different reasoning.

Value

saturation returns a vector of values for the sigma used in the create.smooth function.

Author(s)

Colleter Mathieu and Guitton Jerome.

References

Gascuel et al. (2009) EcoTroph (ET): a trophic level based software for assessing the impacts of fishing on aquatic ecosystems.

See Also

create.smooth function to create the Smooth, plot.smooth.R to plot the smooth function, Transpose.R to calculate the data transposition into trophic spectra, plot.Transpose.R to plot the trophic spectra.

Examples

plot(saturation())
lines(saturation(0.2))
text(48,0.18,"sigma_inf=0.2")
lines(saturation(coeff=0.5))
text(48,0.35,"coeff=0.5")

[Package EcoTroph version 1.1 Index]