Quantile Function

Planck (discrete exponential) distribution quantile function.

The quantile function for a Planck random variable is

for 0 < p < 1 and where λ is the shape parameter.

Installation

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

Usage

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

quantile( p, lambda )

Evaluates the quantile function for a Planck distribution with shape parameter lambda at a probability p.

var y = quantile( 0.8, 0.4 );
// returns 4.0

y = quantile( 0.5, 1.4 );
// returns 0.0

y = quantile( 0.9, 2.1 );
// returns 1.0

If provided an input probability p 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 shape parameter lambda which is nonpositive, the function returns NaN.

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

quantile.factory( lambda )

Returns a function for evaluating the quantile function for a Planck distribution with shape parameter lambda.

var myquantile = quantile.factory( 0.4 );
var y = myquantile( 0.4 );
// returns 1.0

y = myquantile( 0.8 );
// returns 4.0

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-planck-quantile' );

var opts = {
    'dtype': 'float64'
};
var lambda = uniform( 10, 0.1, 10.0, opts );
var p = uniform( 10, 0.0, 1.0, opts );

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

C APIs

Usage

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

stdlib_base_dists_planck_quantile( p, lambda )

Evaluates the quantile function for a Planck (discrete exponential) distribution with probability p and shape parameter lambda.

double out = stdlib_base_dists_planck_quantile( 0.8, 0.4 );
// returns 4.0

The function accepts the following arguments:

• p: [in] double input probability.
• lambda: [in] double shape parameter.

double stdlib_base_dists_planck_quantile( const double p, const double lambda );

Examples

#include "stdlib/stats/base/dists/planck/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 lambda;
    double y;
    int i;

    for ( i = 0; i < 25; i++ ) {
        p = random_uniform( 0.0, 1.0 );
        lambda = random_uniform( 0.1, 5.0 );
        y = stdlib_base_dists_planck_quantile( p, lambda );
        printf( "p: %lf, λ: %lf, Q(p;λ): %lf\n", p, lambda, 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.