randomSubset

Pick an arbitrary subset.

Similar: randomSubset, subsets, isSubset.

function randomSubset(x, n, fr)
// x:  a map
// n:  number of entries [-1 ⇒ any]
// fr: random number generator ([0, 1))

const map = require('extra-map');

var x = new Map([['a', 1], ['b', 2], ['c', 3], ['d', 4]]);
map.randomSubset(x);
// → Map(2) { 'b' => 2, 'c' => 3 }

map.randomSubset(x, 3);
// → Map(3) { 'a' => 1, 'b' => 2, 'd' => 4 }

map.randomSubset(x, 2);
// → Map(2) { 'b' => 2, 'd' => 4 }

References

• shuffle: PHP
• shuffle-seed: @webcaetano
• shuffle-array: @pazguille
• Seeding the random number generator in Javascript