test.js

const util = require('../lib/util')
const assert = require('assert')

/**
 * 
 * @param {Array} actual 
 * @param {Array} excepted 
 * @param {String} message 
 * @param {Number} deviation
 */
let ArrayApproximateEqual = (function () {
    let count = 0
    return function ArrayApproximateEqual(actual, excepted, message, deviation=1e-7) {
        for (let i = 0; i < excepted.length; i++) {
            assert(actual[i] + deviation >= excepted[i], message)
            assert(actual[i] - deviation <= excepted[i], message)
        }
        count++
        console.log(`第${count}个测试通过`)
    }
})()

// root = [-5, 1, 1]
let U = [
    [1, 2, 3],
    [0, 5, 6],
    [0, 0, 1]
]
let y = [0, 11, 1]
ArrayApproximateEqual(util.backSubstitution(U, y), [-5, 1, 1])


// root = [1, 2, 3]
U = [
    [1, 2, 0],
    [1, 1, 2],
    [0, 1, 3]
]
y = [5, 9, 11]
ArrayApproximateEqual(util.chaseMethod(U, y), [1, 2, 3])

// root = [1, 1, 8]
U = [
    [2, 2, -1],
    [1, -1, 0],
    [4, -2, -1]
]
y = [-4, 0, -6]

ArrayApproximateEqual(util.GaussianEliminatio(U, y), [1, 1, 8])

let pai = function(x){
    return 4 / (1 + x * x)
}

let PI = 3.141592653
console.log('PI', util.integral(pai, 0, 1, 100000, algo="T"))
console.log('PI', util.integral(pai, 0, 1, 100000, algo="S"))
console.log('PI', util.integral(pai, 0, 1, 100000, algo="C"))


function func(x, y){
    return -2 * x * y
}

// 0.03916389509898707
console.log('精确解:', 0.03916389509898707)
console.log('EulerFormula', util.EulerFormula(func, 0, 1, 1.8, 1800000))
console.log('RungeKuttaMethod', util.RungeKuttaMethod(func, 0, 1, 1.8, 18000000, 1/2))


let x = [30, 45, 60]
y = [1/2, 0.5 ** 0.5, 0.75 ** 0.5]
console.log(util.diffQuotient(x, y, 2))
console.log(util.NewtonInterpolation(x, y, 2)(50))

let A = [
    [1, 2],
    [3, 4],
]


console.log(util.transport(A, 2, 2))

console.log(util.MatrixOpMtraix(A, '*', A))


A = [
    [2, -1],
    [8, 4],
    [2, 1],
    [7, -1],
    [4, 0]
]

let b = [1, 0, 1, 8, 3]
// [ 0.7927199191102123, -1.4641051567239636 ]
console.log(util.leastSquares(A, b))