import get from 'lodash-es/get.js'
import each from 'lodash-es/each.js'
import map from 'lodash-es/map.js'
import size from 'lodash-es/size.js'
import isnum from 'wsemi/src/isnum.mjs'
import isbol from 'wsemi/src/isbol.mjs'
import iseobj from 'wsemi/src/iseobj.mjs'
import isearr from 'wsemi/src/isearr.mjs'
import cdbl from 'wsemi/src/cdbl.mjs'
import ss from './simpleStatistics.mjs'
import regLine from './regLine.mjs'
/**
* 針對x,y數據進行乘冪(Power)回歸(y=ax^b)
*
* Unit Test: {@link https://github.com/yuda-lyu/w-statistic/blob/master/test/regPower.test.js Github}
* @memberOf w-statistic
* @param {Array} arr 輸入陣列,只提取有效數字(或為字串的數字)進行計算
* @param {Object} [opt={}] 輸入設定物件,預設{}
* @param {Number} [opt.interpX=null] 輸入經由回歸結果內插指定x值數字,預設null
* @param {Boolean} [opt.calcR2=false] 輸入是否計算r2值布林值,預設false
* @param {Boolean} [opt.useSync=false] 輸入是否使用同步函數布林值,預設false
* @returns {Object|Promise} 若useSync=true回傳回歸結果物件,若useSync=false則回傳Promise,此時若成功則resolve回歸結果物件,若失敗則reject錯誤訊息
* @example
*
* async function test() {
*
* let arr
* let r
*
* arr = [
* [1, 2.5],
* [2.5, 1.1],
* [4, 0.5],
* ]
* r = await regPower(arr)
* console.log(r)
* // => { a: 2.6361956497645123, b: -1.1246302189091415 }
*
* arr = [
* [1, 0.5],
* [2.5, 1.1],
* [4, 2.5],
* ]
* r = await regPower(arr)
* console.log(r)
* // => { a: 0.47081085944621165, b: 1.1197632837626978 }
*
* arr = [
* [1, 2.5],
* [2.5, 1.1],
* [4, 0.5],
* ]
* r = await regPower(arr, { interpX: 2 })
* console.log(r)
* // => {
* // a: 2.6361956497645123,
* // b: -1.1246302189091415,
* // interpY: 1.2090108799137966
* // }
*
* arr = [
* [1, 2.5],
* [2.5, 1.1],
* [4, 0.5],
* ]
* r = await regPower(arr, { calcR2: true })
* console.log(r)
* // => {
* // a: 2.6361956497645123,
* // b: -1.1246302189091415,
* // r2: 0.977737578800406
* // }
*
* arr = [
* [1, 2.5],
* [2.5, 1.1],
* [4, 0.5],
* ]
* r = regPower(arr, { useSync: true }) //使用同步函數(sync)
* console.log(r)
* // => { a: 2.6361956497645123, b: -1.1246302189091415 }
*
* }
* test()
* .catch((err) => {
* console.log(err)
* })
*
*/
function regPower(arr, opt = {}) {
//interpX
let interpX = get(opt, 'interpX')
if (!isnum(interpX)) {
interpX = null
}
//calcR2
let calcR2 = get(opt, 'calcR2')
if (!isbol(calcR2)) {
calcR2 = false
}
//useSync
let useSync = get(opt, 'useSync')
if (!isbol(useSync)) {
useSync = false
}
//_sync
let _sync = () => {
//check arr
if (!isearr(arr)) {
throw new Error(`arr is not an effective array`)
}
//rs
let rs = []
each(arr, (v) => {
let x = get(v, 0)
let y = get(v, 1)
if (isnum(x) && isnum(y)) {
x = cdbl(x)
y = cdbl(y)
if (x > 0 && y > 0) {
rs.push([x, y]) //會使用log(x)與log(y)故需大於0
}
}
})
// console.log('rs', rs)
//check
if (size(rs) === 0) {
throw new Error(`no effective data`)
}
//rsLog
let rsLog = map(arr, (v) => {
return [Math.log(v[0]), Math.log(v[1])]
})
//regLine
let rl = regLine(rsLog, { useRegIntercept: true, useSync: true }) //要使用截距, 先簡化使用sync
//check
if (!iseobj(rl)) {
return null
}
//r
let r = {
a: Math.exp(rl.b),
b: rl.m,
}
//interpX
if (isnum(interpX)) {
interpX = cdbl(interpX)
let interpY = r.a * (interpX ** r.b)
r.interpY = interpY
}
//calcR2
if (calcR2) {
// let ys = []
// let yps = []
// each(rs, ([x, y]) => {
// let yp = r.a * (x ** r.b)
// ys.push(y)
// yps.push(yp)
// })
// let r2 = ss.rSquared(ys, yps)
let r2 = ss.rSquared(rs, (x) => r.a * (x ** r.b))
r.r2 = r2
}
return r
}
//_async
let _async = async () => {
let r = null
try {
r = _sync()
if (iseobj(r)) {
return r
}
else {
return Promise.reject(`no effective data`)
}
}
catch (err) {
console.log(err)
return Promise.reject(err.message)
}
}
if (useSync) {
return _sync()
}
else {
return _async()
}
}
export default regPower