MaA: MaA an alternative logistic function commonly used for...

In haddonm/datalowSA: A Package to Faciliate Application of Data poor Stock Assessments

MaA an alternative logistic function commonly used for maturity

Description

MaA - the logistic function exp(a+bxdepend)/(1+exp(a+bxdepend)), which can also be expressed as 1/(1+(1/exp(a + b x depend))). This has the property that the SM50 = -a/b and the interquartile distance is 2.Ln(3)/b.

Usage

MaA(ina, inb, depend)

Arguments

ina	is the intercept of the exponential function
inb	is the gradient of the exponential function
depend	is a vector of lengths/ages for which the logistic maturity value will be calculated

Value

A vector of length(depend) containing the predicted maturity values

Examples

a <- -14.383
b <- 0.146017
lens <- seq(2,210,2)
round(MaA(a,b,depend=lens),5) # length based
round(MaA(-2.5,0.95,0:25),5)   # age based

haddonm/datalowSA documentation built on Nov. 5, 2023, 6:40 p.m.