SchnuteRichards: The five-parameter growth function from Schnute and Richards...

In droglenc/FSA: Simple Fisheries Stock Assessment Methods

The five-parameter growth function from Schnute and Richards (1990).

Description

The five-parameter growth function from Schnute and Richards (1990). Note that this function is slightly modified (a ‘+’ was changed to a ‘-’ so that the ‘a’ parameter will be positive) from the original in Schnute and Richards (1990)

Usage

SchnuteRichards(t, Linf = NULL, k = NULL, a = NULL, b = NULL, c = NULL)

Arguments

t	A numeric vector of ages over which to model growth.
Linf	Mean asymptotic length.
k	The "growth coefficient" with units of (year^(-c)).
a	A dimensionless parameter
b	A dimensionless parameter.
c	A dimensionless parameter.

Value

SchnuteRichards returns a predicted size given the provided parameter values.

IFAR Chapter

None specifically, but 12-Individual Growth is related.

Author(s)

Derek H. Ogle, [e-mail]

References

Schnute, J.T. and L.J. Richards. 1990. A unified approach to the analysis of fish growth, maturity, and survivorship data. Canadian Journal of Fisheries and Aquatic Sciences. 47:24-40.

See Also

See vbFuns, GompertzFuns, RichardsFuns, logisticFuns, and Schnute for similar functionality for other models.

Examples

## See the formulae
growthFunShow("SchnuteRichards",plot=TRUE)

## Simple examples
ages <- 1:15
s1 <- SchnuteRichards(ages,Linf=100,k=0.03,a=0.01,b=0.005,c=2)
plot(s1~ages,type="l",lwd=2)

droglenc/FSA documentation built on Aug. 30, 2023, 12:51 a.m.