Gamma Delta Ratio

Compute the ratio of two gamma functions.

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

var delta;
var z;
var i;

for ( i = 0; i < 100; i++ ) {
    z = randu()*10.0;
    delta = randu()*10.0;
    console.log( 'gamma( %d ) / gamma( %d + %d ) = %d', z, z, delta, gammaDeltaRatio( z, delta ) );
}

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 );
    }
}