gcd

Compute the greatest common divisor (gcd).

The greatest common divisor (gcd) of two non-zero integers a and b is the largest positive integer which divides both a and b without a remainder. The gcd is also known as the greatest common factor (gcf), highest common factor (hcf), highest common divisor, and greatest common measure (gcm).

Installation

npm install @stdlib/math-base-special-gcd

Usage

var gcd = require( '@stdlib/math-base-special-gcd' );

gcd( a, b )

Computes the greatest common divisor (gcd).

var v = gcd( 48, 18 );
// returns 6

If both a and b are 0, the function returns 0.

var v = gcd( 0, 0 );
// returns 0

Both a and b must have integer values; otherwise, the function returns NaN.

var v = gcd( 3.14, 18 );
// returns NaN

v = gcd( 48, 3.14 );
// returns NaN

v = gcd( NaN, 18 );
// returns NaN

v = gcd( 48, NaN );
// returns NaN

Examples

var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var gcd = require( '@stdlib/math-base-special-gcd' );

var a = discreteUniform( 100, 0, 50 );
var b = discreteUniform( a.length, 0, 50 );

var i;
for ( i = 0; i < a.length; i++ ) {
    console.log( 'gcd(%d,%d) = %d', a[ i ], b[ i ], gcd( a[ i ], b[ i ] ) );
}

C APIs

Usage

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

stdlib_base_gcd( a, b )

Computes the greatest common divisor (gcd).

double v = stdlib_base_gcd( 48.0, 18.0 );
// returns 6.0

The function accepts the following arguments:

• a: [in] double input value.
• b: [in] double input value.

double stdlib_base_gcd( const double a, const double b );

Examples

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

int main( void ) {
    const double a[] = { 24.0, 32.0, 48.0, 116.0, 33.0 };
    const double b[] = { 12.0, 6.0, 15.0, 52.0, 22.0 };

    double out;
    int i;
    for ( i = 0; i < 5; i++ ) {
        out = stdlib_base_gcd( a[ i ], b[ i ] );
        printf( "gcd(%lf, %lf) = %lf\n", a[ i ], b[ i ], out );
    }
}

References

• Stein, Josef. 1967. "Computational problems associated with Racah algebra." Journal of Computational Physics 1 (3): 397–405. doi:10.1016/0021-9991(67)90047-2.

See Also

• @stdlib/math-base/special/lcm: compute the least common multiple (lcm).

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 © 2016-2024. The Stdlib Authors.