R/PrecipNitrogen.Rd.R

In USGS-R/smwrData: Example hydrologic data to support statistical methods in water resources

#' Precipitation Water Quality
#' 
#' Ammonia plus organic nitrogen concentrations in precipitation.
#' 
#' 
#' @name PrecipNitrogen
#' @docType data
#' @usage PrecipNitrogen
#' @format Data frame with 20 rows and 2 columns\cr
#' \tabular{lll}{ 
#' Name \tab Type \tab Description\cr\cr
#' NH3plusOrganic \tab numeric \tab Concentration of ammonia plus organic nitrogen\cr
#' Site \tab factor \tab Land-use type\cr
#' }
#' Note: all concentrations are in milligrams per liter as nitrogen.\cr
#'
#' @references Helsel, D.R. and Hirsch, R.M., 2002, Statistical methods in
#' water resources: U.S. Geological Survey Techniques of Water-Resources
#' Investigations, book 4, chap. A3, 522 p.
#' @source Example data in chapter 5 in Helsel and Hirsch (2002)
#' @keywords datasets
#' @examples
#' 
#' data(PrecipNitrogen)
#' # Compare concentrations between residential and industrial land uses
#' with(PrecipNitrogen, boxplot(split(NH3plusOrganic, Site), range=0, log='y'))
#' 
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