R/SnapperHG1.R

In FSAdata: Data to Support Fish Stock Assessment ('FSA') Package

#' @title Age (subsample) and length (all fish) of Snapper from two survey locations.
#' 
#' @description A large sample (not random or proportional) of Snapper (\emph{Pagrus auratus}) were aged from otoliths, with the remainder of the fish just measured for length. Note that age-20 is actually age 19+.
#' 
#' @name SnapperHG1
#' 
#' @docType data
#' 
#' @format A data frame of 18421 observations on the following 3 variables:
#'  \describe{
#'    \item{len}{Measured lengths (cm)}
#'    \item{age}{Ages assigned from examination of otoliths}
#'    \item{survey}{Survey location (\code{KAH8810} or \code{KAH0012})}
#'  }
#'  
#' @section Topic(s):
#'  \itemize{
#'    \item Age-Length Key
#'  }
#'  
#' @concept Age-Length Key
#' 
#' @note The unaged fish were simulated from Table 5 assuming that the total number of fish was large enough that at least one fish was observed in each cell where a  proportion was listed.
#' 
#' @source Recreated from Tables 2, 3, and 5 in Davies, N.M. and C. Walsh. 2002. Snapper age and length samples from Kaharoa research trawl surveys KAH8810 and KAH0012 of the Hauraki Gulf. Final Research Report for Ministry of Fisheries Research Project SNA2000/01. National Institute of Water and Atmospheric Research. [Was (is?) from http://fs.fish.govt.nz/Page.aspx?pk=113&dk=22516.] \href{https://raw.githubusercontent.com/fishR-Core-Team/FSAdata/main/data-raw/SnapperHG1.csv}{CSV file}
#' 
#' @keywords datasets
#' 
#' @examples
#' data(SnapperHG1)
#' str(SnapperHG1)
#' head(SnapperHG1)
#' 
#' ## Extract one of the sample surveys
#' sn1 <- subset(SnapperHG1,survey=="KAH8810")
#' 
#' ## Extract the aged sample
#' sn1.aged <- subset(sn1,!is.na(age))
#' str(sn1.aged)
#' 
#' ## Extract the length sample
#' sn1.length <- subset(sn1,is.na(age))
#' str(sn1.length)
#' 
NULL