Gamma Delta Ratio

Compute the ratio of two gamma functions.

Installation

npm install @stdlib/math-base-special-gamma-delta-ratio

Usage

var gammaDeltaRatio = require( '@stdlib/math-base-special-gamma-delta-ratio' );

gammaDeltaRatio( z, delta )

Computes the ratio of two gamma functions. Specifically, the function evaluates Γ( z ) / Γ( z + delta ).

var y = gammaDeltaRatio( 2.0, 3.0 );
// returns ~0.042

y = gammaDeltaRatio( 4.0, 0.5 );
// returns ~0.516

y = gammaDeltaRatio( 100.0, 0.0 );
// returns 1.0

Examples

var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var gammaDeltaRatio = require( '@stdlib/math-base-special-gamma-delta-ratio' );

var opts = {
    'dtype': 'float64'
};
var z = uniform( 100, 0.0, 10.0, opts );
var delta = uniform( 100, 0.0, 10.0, opts );

logEachMap( 'gamma( %0.4f ) / gamma( %0.4f + %0.4f ) = %0.4f', z, z, delta, gammaDeltaRatio );

C APIs

Usage

#include "stdlib/math/base/special/gamma_delta_ratio.h"

stdlib_base_gamma_delta_ratio( z, delta )

Computes the ratio of two gamma functions. Specifically, the function evaluates Γ( z ) / Γ( z + delta ).

double out = stdlib_base_gamma_delta_ratio( 2.0, 3.0 );
// returns ~0.042

out = stdlib_base_gamma_delta_ratio( 4.0, 0.5 );
// returns ~0.516

The function accepts the following arguments:

• z: [in] double first gamma parameter.
• delta: [in] double difference.

double stdlib_base_gamma_delta_ratio( const double z, const double delta );

Examples

#include "stdlib/math/base/special/gamma_delta_ratio.h"
#include <stdlib.h>
#include <stdio.h>

int main( void ) {
    double delta;
    double out;
    double z;
    int i;

    for ( i = 0; i < 100; i++ ) {
        z = (double)rand() * 10.0;
        delta = (double)rand() * 10.0;
        out = stdlib_base_gamma_delta_ratio( z, delta );
        printf( "gamma_delta_ratio(%lf, %lf) = %lf\n", z, delta, out );
    }
}

See Also

• @stdlib/math-base/special/gamma: gamma function.

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.