mathjs/test/function/trigonometry/coth.test.js

var assert = require('assert'),
    error = require('../../../lib/error/index'),
    math = require('../../../index')(),
    approx = require('../../../tools/approx'),
    pi = math.pi,
    complex = math.complex,
    matrix = math.matrix,
    unit = math.unit,
    coth = math.coth;

describe('coth', function() {
  it('should return the coth of a boolean', function () {
    approx.equal(coth(true), 1.3130352854993);
    approx.equal(coth(false), Number.POSITIVE_INFINITY);
  });

  it('should return the coth of a number', function() {
    approx.equal(coth(0), Number.POSITIVE_INFINITY);
    approx.equal(coth(pi), 1.0037418731973);
    approx.equal(coth(1), 1.3130352854993);
    approx.equal(coth(2), 1.0373147207275);
    approx.equal(coth(3), 1.0049698233137);
  });

  it('should return the coth of a bignumber (downgrades to number)', function() {
    approx.equal(coth(math.bignumber(1)), 1.3130352854993);
  });

  it('should return the coth of a complex number', function() {
    approx.deepEqual(coth(complex('1')), complex(1.3130352854993, 0));
    approx.deepEqual(coth(complex('i')), complex(0, -0.64209261593433));
    approx.deepEqual(coth(complex('2 + i')), complex(0.98432922645819, -0.032797755533753));
  });

  it('should return the coth of an angle', function() {
    approx.equal(coth(unit('90deg')), 1.0903314107274);
    approx.equal(coth(unit('-45deg')), -1.5248686188221);
  });

  it('should throw an error if called with an invalid unit', function() {
    assert.throws(function () {coth(unit('5 celsius'))});
  });

  it('should throw an error if called with a string', function() {
    assert.throws(function () {coth('string')});
  });

  var coth123 = [1.3130352854993, 1.0373147207275, 1.0049698233137];

  it('should return the coth of each element of an array', function() {
    approx.deepEqual(coth([1,2,3]), coth123);
  });

  it('should return the coth of each element of a matrix', function() {
    approx.deepEqual(coth(matrix([1,2,3])), matrix(coth123));
  });

  it('should throw an error in case of invalid number of arguments', function() {
    assert.throws(function () {coth()}, error.ArgumentsError);
    assert.throws(function () {coth(1, 2)}, error.ArgumentsError);
  });
});