R/ChoptankNH3.Rd.R

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

#' Stream Water Quality
#' 
#' Selected ammonia concentration data for Choptank River near Greensboro,
#' Maryland, USGS station number 01491000.
#' 
#' 
#' @name ChoptankNH3
#' @docType data
#' @usage ChoptankNH3
#' @format Data frame with 182 rows and 13 columns\cr
#' \tabular{lll}{ 
#' Name \tab Type \tab Description\cr\cr
#' agency_cd \tab character \tab Agency code\cr
#' site_no \tab character \tab USGS station number\cr
#' sample_dt \tab Date \tab Sample date\cr
#' sample_tm \tab character \tab Sample time\cr
#' time_datum_cd \tab character \tab Time zone datum\cr
#' parm_cd \tab character \tab Parameter code\cr
#' remark_cd \tab character \tab Remark code for the value\cr
#' result_va \tab character \tab Numeric value of the result\cr
#' val_qual_tx \tab character \tab Result value qualifier code\cr
#' meth_cd \tab character \tab Lab method code\cr
#' dqi_cd \tab character \tab Data-quality indicator code\cr
#' rpt_lev_va \tab character \tab Reporting level\cr
#' rpt_lev_cd \tab character \tab Reporting level type\cr
#' } Note: all concentrations in the column
#' result_va are in milligrams per liter as nitrogen.\cr
#'
#' @source Data retrieved from NWISWeb
#' (\url{https://nwis.waterdata.usgs.gov/md/nwis/qwdata}) on 2012-06-18.  Column
#' names are preserved as retrieved, but unnecessary columns were deleted.
#' @keywords datasets
#' @examples
#' 
#' data(ChoptankNH3)
#' # Concentration values plotted over time--black is uncensored, red represents
#' # a less-than value and green are E-coded (less than the reporting level, but
#' # greater than the detection limit).
#' with(ChoptankNH3, plot(sample_dt, result_va, col=as.factor(remark_cd)))
#' 
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