#' Function to return the MH13 hydrologic indicator statistic for a given data frame
#'
#' This function accepts a data frame that contains columns named "discharge", "year_val" and "month_val" and
#' calculates MH13. Variability across maximum monthly flow values. Compute the mean and standard deviation
#' for the maximum monthly flows over the entire flow record. MH13 is the standard deviation times 100
#' divided by the mean maximum monthly flow for all years.
#'
#' @param qfiletempf data frame containing a "discharge" column containing daily flow values
#' @return mh13 numeric value of the standard deviation times 100 divided by the mean maximum monthly flow for the given data frame
#' @export
#' @examples
#' load_data<-paste(system.file(package="HITHATStats"),"/data/obs_data.csv",sep="")
#' qfiletempf<-read.csv(load_data)
#' mh13(qfiletempf)
mh13 <- function(qfiletempf) {
maxmonbyyr <- aggregate(qfiletempf$discharge, list(qfiletempf$year_val,
qfiletempf$month_val), FUN = max, na.rm=TRUE)
colnames(maxmonbyyr) <- c("Year", "Month", "maxmo")
sdmaxmonflows <- sd(maxmonbyyr$maxmo)
meanmaxmonflows <- mean(maxmonbyyr$maxmo)
mh13 <- (sdmaxmonflows * 100)/meanmaxmonflows
return(mh13)
}
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.