Quantile Function

Geometric distribution quantile function.

The quantile function for a geometric random variable is

for 0 < r < 1, where p is the success probability.

Installation

npm install @stdlib/stats-base-dists-geometric-quantile

Usage

var quantile = require( '@stdlib/stats-base-dists-geometric-quantile' );

quantile( r, p )

Evaluates the quantile function for a geometric distribution with success probability p at a value r.

var y = quantile( 0.8, 0.4 );
// returns 3

y = quantile( 0.5, 0.4 );
// returns 1

y = quantile( 0.9, 0.1 );
// returns 21

If provided an input probability r outside the interval [0,1], the function returns NaN.

var y = quantile( 1.9, 0.5 );
// returns NaN

y = quantile( -0.1, 0.5 );
// returns NaN

If provided NaN as any argument, the function returns NaN.

var y = quantile( NaN, 1.0 );
// returns NaN

y = quantile( 0.0, NaN );
// returns NaN

If provided a success probability p outside the interval [0,1], the function returns NaN.

var y = quantile( 0.4, -1.0 );
// returns NaN

y = quantile( 0.4, 1.5 );
// returns NaN

quantile.factory( p )

Returns a function for evaluating the quantile function for a geometric distribution with success probability p.

var myquantile = quantile.factory( 0.4 );
var y = myquantile( 0.4 );
// returns 0

y = myquantile( 0.8 );
// returns 3

y = myquantile( 1.0 );
// returns Infinity

Examples

var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var quantile = require( '@stdlib/stats-base-dists-geometric-quantile' );

var opts = {
    'dtype': 'float64'
};
var p = uniform( 10, 0.0, 1.0, opts );
var r = uniform( 10, 0.0, 1.0, opts );

logEachMap( 'r: %0.4f, p: %0.4f, Q(r;p): %0.4f', r, p, quantile );

C APIs

Usage

#include "stdlib/stats/base/dists/geometric/quantile.h"

stdlib_base_dists_geometric_quantile( r, p )

Evaluates the quantile function for a geometric distribution with success probability p at a value r.

double out = stdlib_base_dists_geometric_quantile( 0.5, 0.4 );
// returns 1

The function accepts the following arguments:

• r: [in] double input probability.
• p: [in] double success probability.

double stdlib_base_dists_geometric_quantile( const double r, const double p );

Examples

#include "stdlib/stats/base/dists/geometric/quantile.h"
#include <stdlib.h>
#include <stdio.h>

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 p;
    double r;
    double y;
    int i;

    for ( i = 0; i < 25; i++ ) {
        r = random_uniform( 0.0, 1.0 );
        p = random_uniform( 0.0, 1.0 );
        y = stdlib_base_dists_geometric_quantile( r, p );
        printf( "r: %lf, p: %lf, Q(r;p): %lf\n", r, p, y );
    }
}

Notice

This package is part of 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, see the main project repository.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2026. The Stdlib Authors.