mirror of
https://github.com/josdejong/mathjs.git
synced 2025-12-08 19:46:04 +00:00
107 lines
4.5 KiB
JavaScript
107 lines
4.5 KiB
JavaScript
// test exp
|
|
import assert from 'assert'
|
|
|
|
import approx from '../../../../tools/approx'
|
|
import math from '../../../../src/bundleAny'
|
|
const mathPredictable = math.create({ predictable: true })
|
|
const complex = math.complex
|
|
const matrix = math.matrix
|
|
const unit = math.unit
|
|
const log2 = math.log2
|
|
|
|
describe('log2', function () {
|
|
it('should return the log base 2 of a boolean', function () {
|
|
assert.strictEqual(log2(true), 0)
|
|
assert.strictEqual(log2(false), -Infinity)
|
|
})
|
|
|
|
it('should return the log base 2 of positive numbers', function () {
|
|
assert.strictEqual(log2(1), 0)
|
|
assert.strictEqual(log2(2), 1)
|
|
approx.deepEqual(log2(3), 1.584962500721156)
|
|
|
|
assert.strictEqual(log2(0.25), -2)
|
|
assert.strictEqual(log2(0.5), -1)
|
|
assert.strictEqual(log2(4), 2)
|
|
assert.strictEqual(log2(8), 3)
|
|
})
|
|
|
|
it('should return the log base 2 of negative numbers', function () {
|
|
approx.deepEqual(log2(-1), complex('0.000000000000000 + 4.532360141827194i'))
|
|
approx.deepEqual(log2(-2), complex('1 + 4.532360141827194i'))
|
|
approx.deepEqual(log2(-3), complex('1.584962500721156 + 4.532360141827194i'))
|
|
})
|
|
|
|
it('should return the log base 2 of negative numbers with predicable:true', function () {
|
|
assert.strictEqual(typeof mathPredictable.log2(-1), 'number')
|
|
assert(isNaN(mathPredictable.log2(-1)))
|
|
})
|
|
|
|
it('should return the log base 2 of zero', function () {
|
|
approx.deepEqual(log2(0), -Infinity)
|
|
})
|
|
|
|
it('should return the log of positive bignumbers', function () {
|
|
const bigmath = math.create({ precision: 100 })
|
|
|
|
assert.deepStrictEqual(bigmath.log2(bigmath.bignumber(1)), bigmath.bignumber(0))
|
|
assert.deepStrictEqual(bigmath.log2(bigmath.bignumber(2)), bigmath.bignumber(1))
|
|
assert.deepStrictEqual(bigmath.log2(bigmath.bignumber(4)), bigmath.bignumber(2))
|
|
assert.deepStrictEqual(bigmath.log2(bigmath.bignumber(8)), bigmath.bignumber(3))
|
|
assert.deepStrictEqual(bigmath.log2(bigmath.bignumber(16)), bigmath.bignumber(4))
|
|
assert.deepStrictEqual(bigmath.log2(bigmath.bignumber(2).pow(500)), bigmath.bignumber(500))
|
|
})
|
|
|
|
it('should return the log of negative bignumbers', function () {
|
|
const bigmath = math.create({ precision: 100 })
|
|
|
|
approx.deepEqual(bigmath.log2(bigmath.bignumber(-1)), bigmath.complex('0.000000000000000 + 4.532360141827194i'))
|
|
approx.deepEqual(bigmath.log2(bigmath.bignumber(-2)), bigmath.complex('1 + 4.532360141827194i'))
|
|
approx.deepEqual(bigmath.log2(bigmath.bignumber(-3)), bigmath.complex('1.584962500721156 + 4.532360141827194i'))
|
|
})
|
|
|
|
it('should return the log of a bignumber with value zero', function () {
|
|
const bigmath = math.create({ precision: 100 })
|
|
|
|
assert.deepStrictEqual(bigmath.log2(bigmath.bignumber(0)).toString(), '-Infinity')
|
|
})
|
|
|
|
it('should throw an error if used with a wrong number of arguments', function () {
|
|
assert.throws(function () { log2() }, /TypeError: Too few arguments/)
|
|
assert.throws(function () { log2(1, 2) }, /TypeError: Too many arguments/)
|
|
})
|
|
|
|
it('should return the log base 2 of a complex number', function () {
|
|
approx.deepEqual(log2(complex(0, 1)), complex('2.2661800709135i'))
|
|
approx.deepEqual(log2(complex(0, -1)), complex('-2.2661800709135i'))
|
|
approx.deepEqual(log2(complex(1, 1)), complex('0.500000000000000 + 1.1330900354567985i'))
|
|
approx.deepEqual(log2(complex(1, -1)), complex('0.500000000000000 - 1.1330900354567985i'))
|
|
approx.deepEqual(log2(complex(-1, -1)), complex('0.500000000000000 - 3.399270106370395i'))
|
|
approx.deepEqual(log2(complex(-1, 1)), complex('0.500000000000000 + 3.399270106370395i'))
|
|
approx.deepEqual(log2(complex(1, 0)), complex(0, 0))
|
|
})
|
|
|
|
it('should throw an error when used on a unit', function () {
|
|
assert.throws(function () { log2(unit('5cm')) })
|
|
})
|
|
|
|
it('should throw an error when used on a string', function () {
|
|
assert.throws(function () { log2('text') })
|
|
})
|
|
|
|
it('should return the log base 2 of each element of a matrix', function () {
|
|
const res = [0, 1, 1.584962500721156, 2]
|
|
approx.deepEqual(log2([1, 2, 3, 4]), res)
|
|
approx.deepEqual(log2(matrix([1, 2, 3, 4])), matrix(res))
|
|
approx.deepEqual(math.divide(log2(matrix([1, 2, 3, 4])), math.LOG2E),
|
|
matrix([0, 0.693147180559945, 1.098612288668110, 1.386294361119891]))
|
|
approx.deepEqual(log2(matrix([[1, 2], [3, 4]])),
|
|
matrix([[0, 1], [1.584962500721156, 2]]))
|
|
})
|
|
|
|
it('should LaTeX log2', function () {
|
|
const expression = math.parse('log2(10)')
|
|
assert.strictEqual(expression.toTex(), '\\log_{2}\\left(10\\right)')
|
|
})
|
|
})
|