mathjs/test/function/probability/multinomial.test.js
2015-05-08 13:20:17 -04:00

33 lines
1.4 KiB
JavaScript

var assert = require('assert'),
error = require('../../../lib/error/index'),
math = require('../../../index'),
multinomial = math.multinomial,
_ = require('underscore');
describe('multinomial', function() {
it('should calculate the multinomial of an array of numbers', function() {
assert.equal(multinomial([1,2,1]), 12);
assert.equal(multinomial([4,2,1]), 105);
assert.equal(multinomial([4,4]), 70);
});
it('should calculate the multinomial of n items taken k at a time with BigNumbers', function() {
assert.equal(_.isEqual(multinomial([math.bignumber(3), math.bignumber(4), math.bignumber(5)]), math.bignumber(27720)),true);
assert.deepEqual(multinomial([math.bignumber(10), math.bignumber(1), math.bignumber(2)]), math.bignumber(858));
});
it('should not work with non-integer and negative input', function() {
assert.throws(function() {multinomial([0.5,3])}, TypeError);
assert.throws(function() {multinomial([math.bignumber(3), math.bignumber(0.5)])}, TypeError);
assert.throws(function() {multinomial([math.bignumber(3.5), math.bignumber(-3)])}, TypeError);
assert.throws(function() {multinomial([math.bignumber(3.5), 1/3])}, TypeError);
});
it('should not work with the wrong number or type of arguments', function() {
assert.throws(function() {multinomial(5, 3, 2)});
assert.throws(function() {multinomial(true, "hello world")});
});
});