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ERAnalysis contains the data from the 23 southbound gray whale surveys conducted from 1967 to 2007. The package also contains the R code developed and used by Laake et al. (2009) to produce their sequence of abundance estimates and variances. Each data table and function are documented.

  • Use of the package requires installing the freely available R software and installing the additional packages ggplot2 and RODBC (
  • After installing R, and the required packages, type library(ERAnalysis) in R to attach the package.
  • Then type ?ERAnalysis to get an overview of the package data and code.
  • Typing example(ERAnalysis) in R will run most of the analysis that was used in Laake et al. (2009).
  • The remainder of the analysis (which takes about 12-24 hours to run) can be executed by copying the code from the example portion of the package help (?ERAnalysis).
  • The package source code with documentation (

A zipped file containing notes, metadata and gray whale database for Access 2003 or higher is available for download here. Please refer to the README.txt inside the zipped file for additional information.

LAAKE, J., A. PUNT, R. HOBBS, M. FERGUSON, D. RUGH, and J. BREIWICK. 2009. Re-analysis of gray whale southbound migration-surveys 1967-2006. NOAA Tech. Memo. NMFS-AFSC-203. (

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