Chondrichthyan Fisheries Biology • mustelus

Tools for chondrichthyan fisheries biology.

Installation

install.packages("mustelus",
  repos = c("https://alharry.r-universe.dev", "https://cloud.r-project.org"))

This installs a pre-built binary from r-universe. Installing from source via GitHub also works, but shouldn’t be necessary:

# install.packages("pak")
pak::pak("alharry/mustelus")

Functions

len_weight() — length–weight regression with bias-corrected predictions, confidence and prediction intervals.
maturity() — length or age at maturity via logistic regression, with bootstrap confidence intervals on $L_{50}$ and $L_{95}$ .
maternity() — length or age at maternity via the three-parameter logistic function of Walker (2005), with $P_{Max}$ either estimated or fixed, implemented in RTMB.
fecundity() — fecundity as a function of length or age by linear regression, with confidence and prediction intervals.
clasp_length() — clasper elongation as a function of length or age by nonlinear (logistic) regression, with bootstrap confidence intervals.
growth() — von Bertalanffy growth parameterised by length at birth, with optional ageing error as a random effect and optional neonate data, implemented in RTMB.
growth_region() — likelihood-based joint confidence regions for $L_\infty$ and $K$ from a growth() fit, following Kimura (1980).

Each returns a tibble with list columns holding the data, coefficients, predictions and fitted model, and has summary() and plot() methods. len_weight() and maturity() accept an optional grouping variable and fit one model per group plus a pooled group. See the articles for worked examples.