99 lines
3.7 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 cot = math.cot
const bigmath = math.create({ number: 'BigNumber', precision: 20 })
describe('cot', function () {
it('should return the cotan of a boolean', function () {
approx.equal(cot(true), 0.642092615934331)
approx.equal(cot(false), Infinity)
})
it('should return the cotan of a number', function () {
approx.equal(cot(0), Infinity)
approx.equal(1 / cot(pi * 1 / 8), 0.414213562373095)
approx.equal(1 / cot(pi * 1 / 4), 1)
approx.equal(cot(pi * 2 / 4), 0)
approx.equal(1 / cot(pi * 3 / 4), -1)
approx.equal(1 / cot(pi * 4 / 4), 0)
approx.equal(1 / cot(pi * 5 / 4), 1)
approx.equal(cot(pi * 6 / 4), 0)
approx.equal(1 / cot(pi * 7 / 4), -1)
approx.equal(1 / cot(pi * 8 / 4), 0)
})
it('should return the cotan of a bignumber', function () {
const Big = bigmath.bignumber
const bigPi = bigmath.pi
const arg1 = Big(0)
const result1 = bigmath.cot(arg1)
assert.ok(!result1.isFinite())
assert.strictEqual(result1.constructor.precision, 20)
assert.deepStrictEqual(arg1, Big(0))
const result2 = bigmath.cot(bigPi.div(8))
assert.deepStrictEqual(result2.toString(), '2.4142135623730950488')
assert.strictEqual(result2.constructor.precision, 20)
assert.strictEqual(bigPi.constructor.precision, 20)
assert.deepStrictEqual(bigmath.cot(bigPi.div(2)), Big('-1.4142135623730950488e-15')) // about zero
assert.deepStrictEqual(bigmath.cot(bigPi), Big('26769019461318409709')) // about infinity
})
it('should return the cotan of a complex number', function () {
const re = 0.00373971037633696
const im = 0.99675779656935837
approx.deepEqual(cot(complex('2+3i')), complex(-re, -im))
approx.deepEqual(cot(complex('2-3i')), complex(-re, im))
approx.deepEqual(cot(complex('-2+3i')), complex(re, -im))
approx.deepEqual(cot(complex('-2-3i')), complex(re, im))
approx.deepEqual(cot(complex('i')), complex(0, -1.313035285499331))
approx.deepEqual(cot(complex('1')), complex(0.642092615934331, 0))
approx.deepEqual(cot(complex('1+i')), complex(0.217621561854403, -0.868014142895925))
})
it('should return the cotan of an angle', function () {
approx.equal(cot(unit('45deg')), 1)
approx.equal(cot(unit('-45deg')), -1)
assert(math.isBigNumber(cot(unit(math.bignumber(45), 'deg'))))
approx.equal(cot(unit(math.bignumber(45), 'deg')).toNumber(), 1)
approx.deepEqual(cot(math.unit(complex('1+i'), 'rad')), complex(0.217621561854403, -0.868014142895925))
})
it('should throw an error if called with an invalid unit', function () {
assert.throws(function () { cot(unit('5 celsius')) })
})
it('should throw an error if called with a string', function () {
assert.throws(function () { cot('string') })
})
const cot123 = [0.642092615934331, -0.457657554360286, -7.015252551434534]
it('should return the cotan of each element of an array', function () {
approx.deepEqual(cot([1, 2, 3]), cot123)
})
it('should return the cotan of each element of a matrix', function () {
approx.deepEqual(cot(matrix([1, 2, 3])), matrix(cot123))
})
it('should throw an error in case of invalid number of arguments', function () {
assert.throws(function () { cot() }, /TypeError: Too few arguments/)
assert.throws(function () { cot(1, 2) }, /TypeError: Too many arguments/)
})
it('should LaTeX cot', function () {
const expression = math.parse('cot(1)')
assert.strictEqual(expression.toTex(), '\\cot\\left(1\\right)')
})
})