Least Common Multiple

Computes the least common multiple (lcm).

Note: the lcm is also known as the lowest common multiple or smallest common multiple and finds common use in calculating the lowest common denominator (lcd).

Installation

$ npm install compute-lcm

For use in the browser, use browserify.

Usage

var lcm = require( 'compute-lcm' );

lcm( a, b[, c,...,n] )

Computes the least common multiple (lcm) of two or more integers.

var val = lcm( 21, 6 );
// returns 42

var val = lcm( 21, 6, 126 );
// returns 126

lcm( arr[, clbk] )

Computes the least common multiple (lcm) of two or more integers.

var val = lcm( [21, 6] );
// returns 42

var val = lcm( [21, 6, 126] );
// returns 126

For object arrays, provide an accessor function for accessing array values.

var data = [
	['beep', 4],
	['boop', 8],
	['bap', 12],
	['baz', 16]
];

function getValue( d, i ) {
	return d[ 1 ];
}

var arr = lcm( arr, getValue );
// returns 48

Notes

• If provided a single integer argument or an array with a length less than 2, the function returns null.

Examples

var lcm = require( 'compute-lcm' );

// Compute the lcm of random tuples...
var x, y, z, arr, val;
for ( var i = 0; i < 100; i++ ) {
	x = Math.round( Math.random()*50 );
	y = Math.round( Math.random()*50 );
	z = Math.round( Math.random()*50 );
	arr = [ x, y, z ];
	val = lcm( arr );
	console.log( arr, val );
}

To run the example code from the top-level application directory,

$ node ./examples/index.js

Tests

Unit

Unit tests use the Mocha test framework with Chai assertions. To run the tests, execute the following command in the top-level application directory:

$ make test

All new feature development should have corresponding unit tests to validate correct functionality.

Test Coverage

This repository uses Istanbul as its code coverage tool. To generate a test coverage report, execute the following command in the top-level application directory:

$ make test-cov

Istanbul creates a ./reports/coverage directory. To access an HTML version of the report,

$ make view-cov

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License

MIT license.

Copyright

Copyright © 2014-2015. Athan Reines.