# TwoSidedPower: Two-Sided Power Distribution In swihart/rmutil: Utilities for Nonlinear Regression and Repeated Measurements Models

## Description

These functions provide information about the two-sided power distribution with location parameter equal to `m` and shape equal to `s`: density, cumulative distribution, quantiles, and random generation.

The two-sided power distribution has density

f(y) = s(y/m)^(s-1), y<=m

f(y) = s((1-y)/(1-m))^(s-1), y>=m

where m is the location parameter of the distribution and s is the shape, and 0<y<1.

For s=1, this is the uniform distribution and for s=2, it is the triangular distribution.

## Usage

 ```1 2 3 4``` ```dtwosidedpower(y, m, s=2, log=FALSE) ptwosidedpower(q, m, s=2) qtwosidedpower(p, m, s=2) rtwosidedpower(n, m, s=2) ```

## Arguments

 `y` vector of responses. `q` vector of quantiles. `p` vector of probabilities `n` number of values to generate `m` vector of location parameters. `s` vector of shape parameters. `log` if TRUE, log probabilities are supplied.

J.K. Lindsey

## References

van Dorp, J.R. and Kotz, S. (2002) A novel extension of the triangular distribution and its parameter estimation. The Statistician 51, 63-79.

`dbeta` for the beta distribution and `dsimplex` for the simplex distribution, other distributions for proportions between zero and one.
 ```1 2 3 4``` ```dtwosidedpower(0.3, 0.5, 3) ptwosidedpower(0.3, 0.5, 3) qtwosidedpower(0.1, 0.5, 3) rtwosidedpower(10, 0.5, 3) ```