#' Imports and processes data from NWIS web service. This function gets the data from here: \url{http://www.waterqualitydata.us}
#' A list of parameter codes can be found here: \url{http://nwis.waterdata.usgs.gov/nwis/pmcodes/}
#' A list of statistic codes can be found here: \url{http://nwis.waterdata.usgs.gov/nwis/help/?read_file=stat&format=table}
#'
#' @param siteNumber string USGS site number. This is usually an 8 digit number
#' @param ParameterCd string USGS parameter code. This is usually an 5 digit number. Multiple parameter codes can be inputted with a ';' separator. Leaving this blank will return all of the measured values during the specified time period.
#' @param StartDate string starting date for data retrieval in the form YYYY-MM-DD.
#' @param EndDate string ending date for data retrieval in the form YYYY-MM-DD.
#' @param interactive logical Option for interactive mode. If true, there is user interaction for error handling and data checks.
#' @keywords data import USGS web service
#' @return retval dataframe with first column dateTime, and at least one qualifier and value columns
#' (subsequent qualifier/value columns could follow depending on requested parameter codes)
#' @export
#' @examples
#' # These examples require an internet connection to run
\item{siteNumber}{string USGS site number. This is usually an 8 digit number}
\item{ParameterCd}{string USGS parameter code. This is usually an 5 digit number. Multiple parameter codes can be inputted with a ';' separator. Leaving this blank will return all of the measured values during the specified time period.}
\item{StartDate}{string starting date for data retrieval in the form YYYY-MM-DD.}
\item{EndDate}{string ending date for data retrieval in the form YYYY-MM-DD.}
\item{interactive}{logical Option for interactive mode. If true, there is user interaction for error handling and data checks.}
}
\value{
retval dataframe with first column dateTime, and at least one qualifier and value columns
(subsequent qualifier/value columns could follow depending on requested parameter codes)
}
\description{
Imports and processes data from NWIS web service. This function gets the data from here: \url{http://www.waterqualitydata.us}
A list of parameter codes can be found here: \url{http://nwis.waterdata.usgs.gov/nwis/pmcodes/}
A list of statistic codes can be found here: \url{http://nwis.waterdata.usgs.gov/nwis/help/?read_file=stat&format=table}
}
\examples{
# These examples require an internet connection to run