Estimate_Growth {AquaticLifeHistory} | R Documentation |
Estimate length-at-age parameters and growth curves for Elasmobranchs
Description
A multi-model growth estimation approach is applied to length-at-age data. Three models can be applied which include the von Bertalanffy (VB), logistic (Log) and Gompertz (Gom) models. AIC values and weights are calculated. The outputs will return a list of model parameter estimates and will either print a plot to the screen or output the length-at-age estimates as part of the list.Use of this function should cite Smart et al. (2016).
Usage
Estimate_Growth(
data,
models = c("VB", "Log", "Gom"),
Birth.Len = NULL,
correlation.matrix = FALSE,
n.bootstraps = 1000,
plots = TRUE,
Max.Age = NULL,
plot.legend = TRUE
)
Arguments
data |
a data frame which includes 'Age' and 'Length - ideally with these names but the function will except some variation to these |
models |
a vector of models to be fitted. These can include" VB", "Log" and "Gom". A subset can also be used |
Birth.Len |
The length-at-birth to be used for two parameter models. If a value is provided, two parameter models are automatically run |
correlation.matrix |
Should the correlation matrix of parameters be returned? This is the only object returned if TRUE. |
n.bootstraps |
The number of bootstraps performed for model 95 confidence intervals |
plots |
Should plots be printed to the screen. If FALSE then the model estimates and CI's are returned as an additional output |
Max.Age |
Specify the max age for bootstrapped confidence intervals to be produced over. Default is the max age in the data. |
plot.legend |
Do you want a legend for the different models on the plot |
Value
Returns a list of parameter estimates with errors and AIC results. If plots is TRUE then a plot is printed to the screen. If plots is FALSE then the length-at-age estimates are returned as a list element
References
Smart et al. (2016) Multi-model approaches in shark and ray growth studies: strengths, weaknesses and the future. Fish and Fisheries. 17: 955-971https://onlinelibrary.wiley.com/doi/abs/10.1111/faf.12154
Examples
# load example data set
data("growth_data")
# Run function with three default model candidates. Use 100 bootstraps for
# testing and then increase to at least 1000 for actual model runs.
Estimate_Growth(growth_data, n.bootstraps = 100)