R/findDupes.R

In CentreForHydrology/CRHMr: Pre- and post- processing for CRHM

#' Finds duplicated datetimes in obs dataframe
#'
#' @description Finds duplicate datetime values. All of the duplicate values are written
#' to a .csv file. Many time series, especially from Environment Canada, may contain
#' duplicate datetimes.
#' @param obs Required. A \pkg{CRHMr} data frame containing obs values.
#' @param dupefile Optional. The name of the output file. If omitted the dupe file will
#' be the name of the obs data frame, followed by \option{_dupedatetimes.csv}.
#' @param quiet Optional. Suppresses display of messages, except for errors. If you are
#' calling this function in an \R script, you will usually leave \code{quiet=TRUE}
#' (i.e. the default). If you are working interactively, you will probably want to set
#' \code{quiet=FALSE}.
#' @param logfile Optional. Name of the file to be used for logging the action.
#' Normally not used.
#' @return If there are duplicate datetimes, returns \code{TRUE}. If there are no
#' duplicates, returns \code{FALSE}.
#' @author Kevin Shook
#' @note If quiet=\code{FALSE}, the function gives a list of the duplicate datetimes.
#' Use this function before removing duplicates and/or interpolation and imputation.
#' Most importantly, use this function before writing values to an obs file. Duplicate
#' datetime values in an obs file will prevent CRHM from executing.
#' @seealso \code{\link{findGaps}} \code{\link{interpolate}} \code{\link{impute}}
#' \code{\link{writeObsFile}}
#' @examples
#' findDupes(BadLake7376, quiet=FALSE)
#' @export


findDupes <- function(obs, dupefile="", quiet=TRUE, logfile=""){
  # Finds duplicate dates in an obs data frame, and writes them to a file
  if (nrow(obs) == 0){
    stop('Missing obs values\n')
  }
  obsName <- deparse(substitute(obs))

  if (dupefile == ''){
    # create file name
    dupefile <- paste(obsName, '_dupedatetimes.csv', sep='')
  }

  # test for duplicates
  dupe.count <- sum(duplicated(obs$datetime))
  if (dupe.count > 0)
    any.dupes <- TRUE
  else
    any.dupes <- FALSE

  if(any.dupes){
    dupes <- duplicated(obs$datetime)
    a <- as.data.frame(obs$datetime[dupes])
    names(a) <- 'duplicate.datetimes'
    write.csv(a, file=dupefile, row.names=FALSE)
  }

  if(!quiet)
    cat(dupe.count, ' duplicate datetimes\n', sep='')

  if (any.dupes)
    output.message <- ' Dupes found'
  else
    output.message <- ' No dDupes found'

  comment <- paste('findDupes obs:', obsName, output.message, sep='')
  result <- logAction(comment, logfile)

  # return either data frame or graph
  if(result)
    return(any.dupes)
  else
    return(result)
}