Skip to contents

Fit von Bertalanffy growth to observed length-at-age

Source: R/fit_basics.R
fit_growth.Rd

Nonlinear least squares, \(L = L_\infty(1 - e^{-k(a + \delta - t_0)})\), on the aged fish of the biological samples. Fish are caught during the year, so the observed (integer) age is shifted by age_offset (0.5 = mid-year) to make t0 comparable with the true value.

Usage

fit_growth(
  data,
  species,
  iter = 1,
  source = NULL,
  years = NULL,
  t0 = NULL,
  age_offset = 0.5
)

Arguments

data

a floss_data or a read_dataset() list.

species

species name.

iter

iteration(s) (pooled).

source

sources to use; default all.

years

years to use; default all.

t0

fix t0 at this value (NULL = estimate).

age_offset

fraction of a year added to observed ages.

Value

a floss_fit with pars (linf, k, t0).