R/medflowbyyear.R

In jlthomps/EflowStats: Returns HIT/HAT Hydrologic Indicator stats for a given set of data

#' Function to return the median flow by year for a given data frame
#' 
#' This function accepts a data frame that contains columns named "discharge" and "year_val" and 
#' calculates the median flow by year for the entire record
#' 
#' @param qfiletempf data frame containing a "discharge" column containing daily flow values
#' @return medflowbyyear numeric value of the median flow by year for the given data frame
#' @export
#' @examples
#' qfiletempf<-sampleData
#' medflowbyyear(qfiletempf)
medflowbyyear <- function(qfiletempf) {
  medflowbyyear<-aggregate(qfiletempf$discharge, list(qfiletempf$year_val), 
                           median, na.rm=TRUE)
  return(medflowbyyear)
}