94 lines
3.5 KiB
JavaScript

import assert from 'assert'
import math from '../../../../src/bundleAny'
import approx from '../../../../tools/approx'
const pi = math.pi
const complex = math.complex
const matrix = math.matrix
const unit = math.unit
const tan = math.tan
const piBigmath = math.create({ number: 'BigNumber', precision: 21 })
const bigmath = math.create({ precision: 20 })
const Big = bigmath.bignumber
const bigTan = bigmath.tan
describe('tan', function () {
it('should return the tangent of a boolean', function () {
approx.equal(tan(true), 1.55740772465490)
approx.equal(tan(false), 0)
})
it('should return the tangent of a number', function () {
approx.equal(tan(0), 0)
approx.equal(tan(pi * 1 / 4), 1)
approx.equal(tan(pi * 1 / 8), 0.414213562373095)
assert.ok(tan(pi * 2 / 4) > 1e10)
approx.equal(tan(pi * 3 / 4), -1)
approx.equal(tan(pi * 4 / 4), 0)
approx.equal(tan(pi * 5 / 4), 1)
assert.ok(tan(pi * 6 / 4) > 1e10)
approx.equal(tan(pi * 7 / 4), -1)
approx.equal(tan(pi * 8 / 4), 0)
})
it('should return the tangent of a bignumber', function () {
const bigPi = piBigmath.pi
assert.deepStrictEqual(bigTan(Big(0)), Big(0))
assert.deepStrictEqual(bigTan(Big(-1)), Big('-1.5574077246549022305'))
assert.deepStrictEqual(bigTan(bigPi.div(8)).toString(), '0.414213562373095048802')
// Wolfram: 0.414213562373095048801688724209698078569671875376948073176
assert.deepStrictEqual(bigTan(bigPi.div(4)).toString(), '0.999999999999999999999')
})
it('should return the tangent of a complex number', function () {
const re = 0.00376402564150425
const im = 1.00323862735360980
approx.deepEqual(tan(complex('2+3i')), complex(-re, im))
approx.deepEqual(tan(complex('2-3i')), complex(-re, -im))
approx.deepEqual(tan(complex('-2+3i')), complex(re, im))
approx.deepEqual(tan(complex('-2-3i')), complex(re, -im))
approx.deepEqual(tan(complex('i')), complex(0, 0.761594155955765))
approx.deepEqual(tan(complex('1')), complex(1.55740772465490, 0))
approx.deepEqual(tan(complex('1+i')), complex(0.271752585319512, 1.083923327338695))
})
it('should return the tangent of an angle', function () {
approx.equal(tan(unit(' 60deg')), math.sqrt(3))
approx.equal(tan(unit('-135deg')), 1)
assert(math.isBigNumber(tan(unit(math.bignumber(60), 'deg'))))
approx.equal(tan(unit(math.bignumber(60), 'deg')).toNumber(), math.sqrt(3))
approx.deepEqual(tan(unit(complex('1+i'), 'rad')), complex(0.271752585319512, 1.083923327338695))
})
it('should throw an error if called with an invalid unit', function () {
assert.throws(function () { tan(unit('5 celsius')) })
})
it('should throw an error if called with a string', function () {
assert.throws(function () { tan('string') })
})
const tan123 = [1.557407724654902, -2.185039863261519, -0.142546543074278]
it('should return the tan of each element of an array', function () {
approx.deepEqual(tan([1, 2, 3]), tan123)
})
it('should return the tan of each element of a matrix', function () {
approx.deepEqual(tan(matrix([1, 2, 3])), matrix(tan123))
})
it('should throw an error in case of invalid number of arguments', function () {
assert.throws(function () { tan() }, /TypeError: Too few arguments/)
assert.throws(function () { tan(1, 2) }, /TypeError: Too many arguments/)
})
it('should LaTeX tan', function () {
const expression = math.parse('tan(1)')
assert.strictEqual(expression.toTex(), '\\tan\\left(1\\right)')
})
})