fishmethods (version 1.13-1)

clus.vb.fit: Fit a Von Bertalanffy growth equation to clustered data via bootstrapping

Description

Fits the von Bertalanffy growth equation to clustered length and age by using nonlinear least-squares and by bootstrapping clusters

Usage

clus.vb.fit(len = NULL, age = NULL, cluster = NULL, nboot = 1000,
sumtype = 1, control = list(maxiter=10000, minFactor=1/1024,tol=1e-5))

Value

List containing a summary of successful model fits and parameter estimates, standard errors and 95 percent confidence intervals, and the average correlation matrix.

Arguments

len

vector of lengths of individual fish

age

vector of ages of individual fish

cluster

haul or cluster membership identifier

nboot

number of bootstrap samples

sumtype

use 1 = mean or 2 = median of bootstrap runs as the parameter and correlation coefficients values. Default is 1.

control

see control under function nls.

Author

Gary A. Nelson, Massachusetts Division of Marine Fisheries

Details

A standard von Bertalanffy growth curve is fitted to length-at-age data of each nboot sample of clusters using nonlinear least-squares (function nls). Standard errors are calculated using function sd applied to bootstrap parameters.

Examples

  if (FALSE) {
	data(pinfish)
	with(pinfish,clus.vb.fit(len=sl,age=age,cluster=field_no,nboot=100))
  }