R/flow.duration.r.R

In IHA: This package implements The Nature Conservancy's Indicators of Hydrologic Alteration software in R.

#'Plot a flow duration curve
#'
#'Plots a flow duration curve using ecdf() function
#'@param x a zoo object containing flow data
#'@param ylab a y axis label
#'@param xlab an x axis label
#'@param ... additional arguments passed to plot
#'@export
flow.duration <- function(x, ylab = 'Flow', xlab = 'Exceedance probability', ...){
	cdf <- ecdf(coredata(x))
	#cdf <- plot.stepfun(cdf.stepfun)
  assign('y', with(environment(cdf), 1-y), envir = environment(cdf))
  assign('yleft', 1, envir = environment(cdf))
  assign('yright', 0, envir = environment(cdf))
	#plot(1- cdf$y, cdf$t[-1], log = log, type = 'l', xlab = xlab, ylab = ylab, ...)
  class(cdf) <- class(cdf)[-1]
  plot(cdf, main = 'Flow duration curve', ylab = 'Probability Flow is Exceeded',
       xlab = 'Flow', xlim = range(coredata(x)), ...)
  invisible(cdf)
}