Cauchy distribution quantile function.
npm install @stdlib/stats-base-dists-cauchy-quantileWe believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js. The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases. When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there. To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!
About stdlib...
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]
> [Cauchy][cauchy-distribution] distribution [quantile function][quantile-function].
The [quantile function][quantile-function] for a [Cauchy][cauchy-distribution] random variable is
for 0 <= p <= 1, where x0 is the location parameter and gamma > 0 is the scale parameter.
``bash`
npm install @stdlib/stats-base-dists-cauchy-quantile
`javascript`
var quantile = require( '@stdlib/stats-base-dists-cauchy-quantile' );
#### quantile( p, x0, gamma )
Evaluates the [quantile function][quantile-function] for a [Cauchy][cauchy-distribution] distribution with parameters x0 (location parameter) and gamma > 0 (scale parameter).
`javascript
var y = quantile( 0.5, 0.0, 1.0 );
// returns 0.0
y = quantile( 0.2, 4.0, 2.0 );
// returns ~1.247
y = quantile( 0.9, 4.0, 2.0 );
// returns ~10.155
`
If provided a probability p outside the interval [0,1], the function returns NaN.
`javascript
var y = quantile( 1.9, 0.0, 1.0 );
// returns NaN
y = quantile( -0.1, 0.0, 1.0 );
// returns NaN
`
If provided NaN as any argument, the function returns NaN.
`javascript
var y = quantile( NaN, 0.0, 1.0 );
// returns NaN
y = quantile( 0.0, NaN, 1.0 );
// returns NaN
y = quantile( 0.0, 0.0, NaN );
// returns NaN
`
If provided gamma <= 0, the function returns NaN.
`javascript
var y = quantile( 0.4, 0.0, -1.0 );
// returns NaN
y = quantile( 0.4, 0.0, 0.0 );
// returns NaN
`
#### quantile.factory( x0, gamma )
Returns a function for evaluating the [quantile function][quantile-function] of a [Cauchy][cauchy-distribution] distribution with location parameter x0 and scale parameter gamma > 0.
`javascript
var myquantile = quantile.factory( 10.0, 2.0 );
var y = myquantile( 0.2 );
// returns ~7.247
y = myquantile( 0.8 );
// returns ~12.753
`
`javascript
var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var EPS = require( '@stdlib/constants-float64-eps' );
var quantile = require( '@stdlib/stats-base-dists-cauchy-quantile' );
var opts = {
'dtype': 'float64'
};
var gamma = uniform( 10, EPS, 20.0, opts );
var x0 = uniform( 10, -5.0, 5.0, opts );
var p = uniform( 10, 0.0, 1.0, opts );
logEachMap( 'p: %0.4f, x0: %0.4f γ: %0.4f, Q(p;x0,γ): %0.4f', p, x0, gamma, quantile );
`
*
`c`
#include "stdlib/stats/base/dists/cauchy/quantile.h"
#### stdlib_base_dists_cauchy_quantile( p, x0, gamma )
Evaluates the [quantile function][quantile-function] of a [Cauchy][cauchy-distribution] distribution with location parameter x0 and scale parameter gamma.
`c`
double out = stdlib_base_dists_cauchy_quantile( 0.3, 2.0, 2.0 );
// returns ~0.547
The function accepts the following arguments:
- p: [in] double probability.[in] double
- x0: location parameter.[in] double
- gamma: scale parameter.
`c`
double stdlib_base_dists_cauchy_quantile( const double p, const double x0, const double gamma );
`c
#include "stdlib/stats/base/dists/cauchy/quantile.h"
#include "stdlib/constants/float64/eps.h"
#include
#include
static double random_uniform( const double min, const double max ) {
double v = (double)rand() / ( (double)RAND_MAX + 1.0 );
return min + ( v*(max-min) );
}
int main( void ) {
double gamma;
double x0;
double y;
double p;
int i;
for ( i = 0; i < 25; i++ ) {
p = random_uniform( 0.0, 1.0 );
x0 = random_uniform( -5.0, 5.0 );
gamma = random_uniform( STDLIB_CONSTANT_FLOAT64_EPS, 20.0 );
y = stdlib_base_dists_cauchy_quantile( p, x0, gamma );
printf( "p: %lf, x0: %lf, γ: %lf, Q(p;x0,γ): %lf\n", p, x0, gamma, y );
}
}
`
*
This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.
For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].
#### Community
[![Chat][chat-image]][chat-url]
---
See [LICENSE][stdlib-license].
Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
[npm-image]: http://img.shields.io/npm/v/@stdlib/stats-base-dists-cauchy-quantile.svg
[npm-url]: https://npmjs.org/package/@stdlib/stats-base-dists-cauchy-quantile
[test-image]: https://github.com/stdlib-js/stats-base-dists-cauchy-quantile/actions/workflows/test.yml/badge.svg?branch=v0.3.1
[test-url]: https://github.com/stdlib-js/stats-base-dists-cauchy-quantile/actions/workflows/test.yml?query=branch:v0.3.1
[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/stats-base-dists-cauchy-quantile/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/stats-base-dists-cauchy-quantile?branch=main
[chat-image]: https://img.shields.io/badge/zulip-join_chat-brightgreen.svg
[chat-url]: https://stdlib.zulipchat.com
[stdlib]: https://github.com/stdlib-js/stdlib
[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors
[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules
[deno-url]: https://github.com/stdlib-js/stats-base-dists-cauchy-quantile/tree/deno
[deno-readme]: https://github.com/stdlib-js/stats-base-dists-cauchy-quantile/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/stats-base-dists-cauchy-quantile/tree/umd
[umd-readme]: https://github.com/stdlib-js/stats-base-dists-cauchy-quantile/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/stats-base-dists-cauchy-quantile/tree/esm
[esm-readme]: https://github.com/stdlib-js/stats-base-dists-cauchy-quantile/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/stats-base-dists-cauchy-quantile/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/stats-base-dists-cauchy-quantile/main/LICENSE
[quantile-function]: https://en.wikipedia.org/wiki/Quantile_function
[cauchy-distribution]: https://en.wikipedia.org/wiki/Cauchy_distribution