selFcn.DoubleNormal: Calculate a double normal selectivity function

In wStockhausen/tcsamFunctions: Functions related to the BSAI Tanner crab stock assessment (2015+)

Calculate a double normal selectivity function

Description

Function to calculate (and optionally plot the components of) a double normal selectivity function.

Usage

selFcn.DoubleNormal(x, params, showPlot = FALSE, test = FALSE)

Arguments

x	: age/size bins at which to compute values
params	: vector of parameters (see Details)
showPlot	: flag (T/F) to plot components of function
test	: flag (T/F) to output list with detailed info (T) rather than just vector of sel function values (F)

Details

The params vector elements are:

• 1: location of ascending peak

• 2: logistic scale width of plateau

• 3: ascending slope (NOT log scale; i.e. = exp(p[3]) if p[3] from SS)

• 3: descending slope (NOT log scale; i.e. = exp(p[4]) if p[4] from SS)

• 5: logistic scale value in initial bin; i.e. initial = 1./(1.+exp(-params[5]));

• 6: logistic scale value in final bin; i.e. final = 1./(1.+exp(-params[6]));

wStockhausen/tcsamFunctions documentation built on Jan. 28, 2024, 9:01 a.m.