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87 lines
3.2 KiB
JavaScript
87 lines
3.2 KiB
JavaScript
const assert = require('assert')
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const math = require('../../../src/main')
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const BigNumber = math.type.BigNumber
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const Complex = math.type.Complex
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const DenseMatrix = math.type.DenseMatrix
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const Unit = math.type.Unit
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const variance = math['var']
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describe('variance', function () {
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it('should return the variance of numbers', function () {
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assert.equal(variance(5), 0)
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assert.equal(variance(2, 4, 6), 4)
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})
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it('should return the variance of big numbers', function () {
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assert.deepEqual(variance(new BigNumber(2), new BigNumber(4), new BigNumber(6)),
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new math.type.BigNumber(4))
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})
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it('should return the variance of complex numbers', function () {
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assert.deepEqual(variance(new Complex(2, 3), new Complex(-1, 2)), new Complex(4, 3))
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})
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it('should return the variance of mixed numbers and complex numbers', function () {
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assert.deepEqual(variance(2, new Complex(-1, 3)), new Complex(0, -9))
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})
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it('should return the variance from an array', function () {
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assert.equal(variance([2, 4, 6]), 4)
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assert.equal(variance([5]), 0)
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})
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it('should return the uncorrected variance from an array', function () {
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assert.equal(variance([2, 4], 'uncorrected'), 1)
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assert.equal(variance([2, 4, 6, 8], 'uncorrected'), 5)
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})
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it('should return the biased variance from an array', function () {
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assert.equal(variance([2, 8], 'biased'), 6)
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assert.equal(variance([2, 4, 6, 8], 'biased'), 4)
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})
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it('should throw an error in case of unknown type of normalization', function () {
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assert.throws(function () { variance([2, 8], 'foo') }, /Unknown normalization/)
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})
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it('should return the variance from an 1d matrix', function () {
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assert.equal(variance(new DenseMatrix([2, 4, 6])), 4)
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assert.equal(variance(new DenseMatrix([5])), 0)
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})
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it('should return the variance element from a 2d array', function () {
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assert.deepEqual(variance([
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[2, 4, 6],
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[1, 3, 5]
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]), 3.5)
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})
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it('should return the variance element from a 2d matrix', function () {
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assert.deepEqual(variance(new DenseMatrix([
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[2, 4, 6],
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[1, 3, 5]
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])), 3.5)
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})
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it('should throw an error if called with invalid number of arguments', function () {
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assert.throws(function () { variance() })
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})
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it('should throw an error if called with invalid type of arguments', function () {
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assert.throws(function () { variance(new Date(), 2) }, /Cannot calculate var, unexpected type of argument/)
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assert.throws(function () { variance(new Unit(5, 'cm'), new Unit(10, 'cm')) }, /Cannot calculate var, unexpected type of argument/)
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assert.throws(function () { variance(2, 3, null) }, /Cannot calculate var, unexpected type of argument/)
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assert.throws(function () { variance([2, 3, null]) }, /Cannot calculate var, unexpected type of argument/)
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assert.throws(function () { variance([2, 3, 4], 5) }, /Unknown normalization "5"/)
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})
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it('should throw an error if called with an empty array', function () {
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assert.throws(function () { variance([]) })
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})
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it('should LaTeX var', function () {
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const expression = math.parse('var(1,2,3)')
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assert.equal(expression.toTex(), '\\mathrm{Var}\\left(1,2,3\\right)')
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})
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})
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