mathjs/test/function/probability/combinations.test.js

31 lines
1.1 KiB
JavaScript

var assert = require('assert'),
math = require('../../../index')(),
combinations = math.combinations;
describe('combinations', function() {
it('should calculate the combinations of a number taking k at a time', function() {
assert.equal(combinations(0, 0), 1);
assert.equal(combinations(7, 5), 21);
assert.equal(combinations(20, 15), 15504);
assert.equal(combinations(63, 7), 553270671);
});
it('should calculate the combinations of n items taken k at a time with BigNumbers', function() {
assert.deepEqual(combinations(math.bignumber(7), math.bignumber(5)), math.bignumber(21));
assert.deepEqual(combinations(math.bignumber(20), math.bignumber(15)), math.bignumber(15504));
});
it('should not work with non-integer and negative input', function() {
assert.throws(function() {combinations(0.5, 3)});
assert.throws(function() {combinations(3, 5)});
});
it('should not work with the wrong number or type of arguments', function() {
assert.throws(function() {combinations(5, 3, 2)});
assert.throws(function() {combinations(true, "hello world")});
});
});