# percentile.ple: Calculate Nonparametric Estimate of Xp and Confidence Limits In STAND: Statistical Analysis of Non-Detects

## Description

Find Xp, the 100pth percentile, and the 100γ% nonparametric confidence limits from PLE of F(x).

## Usage

 `1` ```percentile.ple(dd, p = 0.95, gam = 0.95, interp = TRUE) ```

## Arguments

 `dd` An n by 2 matrix or data frame with x (exposure) variable in column 1, and det= 0 for non-detect or 1 for detect in column 2 `p` Find x such that the PLE of F(x) = `p`. Default 0.95 `gam` one-sided confidence level γ. Default is 0.95 `interp` if `interp` is `TRUE` use linear interpolation. Default `TRUE`

## Details

Find Xp the 100pth percentile and confidence limits from the PLE of F(x) – see `plekm` for additional details. If interp is `TRUE` use linear interpolation; otherwise, the upper confidence limit (UCL) for Xp, UX(`p`,γ), is the smallest value of x such that the LCL for F(x) is `p`, the lower confidence limit (LCL), LX(`p`,γ), is the largest value of x such that the UCL for F(x) is `p`.

## Value

A list with components:

 `Xp` PLE of the 100pth percentile `LXp` PLE of LX(`p`,γ) the 100*γ% LCL for Xp `UXp` PLE of UX(`p`,γ) the 100*γ% UCL for Xp `p` probability for Xp the 100pth percentile `gam` one-sided confidence level γ. Default is 0.95

E. L. Frome

## References

Frome, E. L. and Wambach, P. F. (2005), "Statistical Methods and Software for the Analysis of Occupational Exposure Data with Non-Detectable Values," ORNL/TM-2005/52,Oak Ridge National Laboratory, Oak Ridge, TN 37830. Available at: http://www.csm.ornl.gov/esh/aoed/ORNLTM2005-52.pdf

See Also as `plekm` and `SESdata`
 ```1 2 3 4 5``` ```# use data from example 2 in ORNL/TM-2005/52 to calculate # 95 percent UCL for 95th percentile data(beTWA) unlist(percentile.ple(beTWA)) unlist(percentile.ml(beTWA)) # compare ML estimates ```