Compute the greatest common divisor (gcd).
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> Compute the [greatest common divisor][gcd] (gcd).
The [greatest common divisor][gcd] (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).
``bash`
npm install @stdlib/math-base-special-gcd
`javascript`
var gcd = require( '@stdlib/math-base-special-gcd' );
#### gcd( a, b )
Computes the [greatest common divisor][gcd] (gcd).
`javascript`
var v = gcd( 48, 18 );
// returns 6
If both a and b are 0, the function returns 0.
`javascript`
var v = gcd( 0, 0 );
// returns 0
Both a and b must have integer values; otherwise, the function returns NaN.
`javascript
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
`
`javascript
var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var gcd = require( '@stdlib/math-base-special-gcd' );
var opts = {
'dtype': 'float64'
};
var a = discreteUniform( 100, 0, 50, opts );
var b = discreteUniform( a.length, 0, 50, opts );
logEachMap( 'gcd(%d,%d) = %d', a, b, gcd );
`
*
`c`
#include "stdlib/math/base/special/gcd.h"
#### stdlib_base_gcd( a, b )
Computes the greatest common divisor (gcd).
`c`
double v = stdlib_base_gcd( 48.0, 18.0 );
// returns 6.0
The function accepts the following arguments:
- a: [in] double input value.[in] double
- b: input value.
`c`
double stdlib_base_gcd( const double a, const double b );
`c
#include "stdlib/math/base/special/gcd.h"
#include
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 );
}
}
`
- 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][@stein:1967].
*
- [@stdlib/math-base/special/lcm][@stdlib/math/base/special/lcm]: compute the least common multiple (lcm).
*
This package is part of [stdlib][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][stdlib], see the main project [repository][stdlib].
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---
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Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
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[gcd]: https://en.wikipedia.org/wiki/Greatest_common_divisor
[@stein:1967]: https://doi.org/10.1016/0021-9991(67)90047-2
[@stdlib/math/base/special/lcm]: https://www.npmjs.com/package/@stdlib/math-base-special-lcm