R/get_rivers.R

In danStich/anadrofish: Anadromous Fish Population Responses to Habitat Changes

#' @title Rivers included in habitat data by species
#'
#' @description Get names of rivers included in package for each species.
#'
#' @details The primary uses of this function are (1) so the user can see 
#' rivers that can be used for simulation, and (2) so the output can be passed 
#' to a random sampler for use in stochastic simulation via 
#' parallel processing.
#' 
#' @param species Species for which rivers are returned
#' Choices include American shad (\code{"AMS"}), alewife (\code{"ALE"}), and
#' blueback herring (\code{"BBH"}).
#'
#' @return A character vector of rivers that are included in 
#' built-in habitat datasets for selected \code{species}.
#'
#' @example inst/examples/get_rivers_ex.R
#'
#' @export
#'
get_rivers <- function(species = c("ALE", "AMS", "BBH")){
  
  # Make sure species is one of those implemented in package
  if(!species %in% c('ALE', 'AMS', 'BBH')){
    stop("
         
    Argument 'species' must be one of 'ALE', 'AMS', or 'BBH'.") 
  }
  
  if(species == "AMS"){
    return(sort(unique(anadrofish::habitat$system)))
  }
  if(species == "ALE"){
    return(sort(unique(anadrofish::habitat_ale$River_huc)))
  }  
  if(species == "BBH"){
    return(sort(unique(anadrofish::habitat_bbh$River_huc)))
  }    
}