ml-combinations

combinations

Generate all possible unordered samples of size m, without replacement, from a set of n objects

Very low memory footprint even if the number of combinations to generate is high.

Installation

$ npm install ml-combinations

Usage

// the package exports a generator function
const combinations = require('ml-combinations');
const options = {mode: 'index'};

// the generator function returns an iterator
var gen = combinations(2, 4, options);

// You can loop throw the iterator
for(let combination of gen) {
    console.log(combination);
}

// Or use destructuring
console.log([...gen]); // [ [ 3, 2 ], [ 0, 2 ], [ 1, 2 ], [ 1, 2 ], [ 0, 2 ], [ 0, 1 ] ]

// Use mask mode instead of index mode (index mode is the default)
options.mode = 'mask';
gen = combinations(2, 4, options);
console.log([...gen]); // [ [ 0, 0, 1, 1 ][ 1, 0, 0, 1 ],[ 0, 1, 0, 1 ],[ 0, 1, 1, 0 ],[ 1, 0, 1, 0 ],[ 1, 1, 0, 0 ] ]

References

Phillip J Chase, `Algorithm 382: Combinations of M out of N Objects [G6]', Communications of the Association for Computing Machinery 13:6:368 (1970). To the article

License

MIT

Changelog

1.0.1 (2016-07-21)

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