README.Rmd

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output: github_document
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```{r, echo = FALSE}
knitr::opts_chunk$set(
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  fig.path = "tools/README-"
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[![CRAN_Status_Badge](http://www.r-pkg.org/badges/version/logitnorm)](http://cran.r-project.org/package=logitnorm)
[![Travis-CI Build Status](https://travis-ci.org/bgctw/logitnorm.svg?branch=master)](https://travis-ci.org/bgctw/logitnorm)


## Overview

`logitnorm` package provides support for the univariate
[logit-normal
distribution](https://en.wikipedia.org/wiki/Logit-normal_distribution). In
addition to the usual random, density, percentile, and quantile function, it
helps with estimating distribution parameters from observations statistics.

## Installation

```{r, eval = FALSE}
# From CRAN
install.packages("logitnorm")

# Or the the development version from GitHub:
# install.packages("devtools")
devtools::install_github("bgctw/logitnorm")
```

## Usage

See the package vignette for an introduction.

A simple example estimates distribution parameters from observation
statistics of mode 0.7 and upper quantile 0.9. Next, the density is
computed and plotted across a range of quantiles.
 
```{r example}
(theta <- twCoefLogitnormMLE(0.7,0.9))
x <- seq(0,1, length.out=81) 
d <- dlogitnorm(x, mu=theta[1,"mu"], sigma=theta[1,"sigma"])
plot(d~x,type="l")
abline(v=c(0.7,0.9), col="grey")
```