calc_exceedance: Calculate Exceedance Probability

In mps9506/mpsrf: Miscellaneous R Functions

Description

Calculates the exceedance probability, or the flow-duration percentile.

Usage

calc_exceedance(x, ties = "min")

Arguments

x	a vector of values. Missing values are left as is. If you want to treat as zero, replace with 0. if you want to treat them as the smallest value, replace with -Inf before applying the function.
ties	How to handle ties in ranked values. One of c("average", "first", "last", " random", "max", "min"). Defaults to "min".

Details

x must be a vector of positive numeric values. The exceedance probability is calculated as:

\loadmathjax \mjsdeqn

P = \fracmn+1

where

\mjseqn

P is the exceedance probability,

\mjseqn

m is the descending rank value,

\mjseqn

n is the total number of values

Value

A vector of length x of the exceedance probability for each value of x.

References

Searcy, J. C. (1959). Manual of hydrology, 2, Low flow techniques, flow duration curves. US Geol. Surv. Water Supply Pap, 1542.

Examples

x <- seq(1:100)
calc_exceedance(x)

mps9506/mpsrf documentation built on Sept. 25, 2020, 9:33 a.m.