w-statistic/src/arrGammaInv.mjs

A tool for statistical analysis.

import get from 'lodash-es/get.js'
import size from 'lodash-es/size.js'
import isarr from 'wsemi/src/isarr.mjs'
import isnum from 'wsemi/src/isnum.mjs'
import ispint from 'wsemi/src/ispint.mjs'
import cdbl from 'wsemi/src/cdbl.mjs'
import cint from 'wsemi/src/cint.mjs'
import arrGammaFit from './arrGammaFit.mjs'
import jt from './jStat.mjs'


/**
 * 基於Gamma累加分布計算指定位置之反函數值
 *
 * Unit Test: {@link https://github.com/yuda-lyu/w-statistic/blob/master/test/arrGammaInv.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 {Number} ratio 輸入指定位置浮點數，需介於0至1之間
 * @returns {Number} 回傳反函數值
 * @example
 *
 * async function test() {
 *
 *     let arr
 *     let r
 *
 *     arr = [12, 36, 9, 13, 6, 17, 7, 12, 31, 57, 44, 32, 16, 11, 10, 38, 31, 28, 26, 7, 16, 16, 16, 13, 7, 8, 12, 17, 11, 20, 7, 6, 14, 7, 37, 11, 7, 8, 8, 32, 29, 52, 20, 6, 11, 12, 33, 48, 10, 27, 11, 24, 17, 11, 23, 20, 13, 16, 16, 17, 13, 15, 13, 26, 11, 13, 29, 18, 18, 13, 11, 12, 9, 17, 19, 14, 19, 9, 37, 32, 14, 20, 13, 22, 12, 14, 33, 15, 20, 37, 24, 19, 15, 15, 5, 11, 13, 60, 39, 17, 6, 18, 40, 21, 18, 17, 12, 12, 10, 39, 27, 10, 8, 44, 36, 18, 11, 8, 13, 9, 25, 11, 10, 55, 54, 13, 8, 19, 38, 9, 17, 14, 9, 12, 54, 22, 11, 19, 50, 18, 12, 40, 52, 12, 15, 7, 12, 15, 18, 19, 11, 43, 23, 14, 25, 32, 23, 15, 12, 20, 14, 10, 12, 24, 50, 40, 16, 14, 9, 27, 9, 11, 17, 19, 12, 17, 14, 5, 24, 22, 60, 20, 9, 11, 11, 6, 7, 8, 31, 10, 12, 9, 11, 26, 14, 7, 14, 57, 19, 9, 10, 9, 19, 19, 15, 21, 48, 23, 26, 14, 46, 51, 10, 10, 9, 7, 19, 46, 27, 18, 12, 10, 36, 15, 5, 11, 13, 21, 15, 15, 16, 29, 44, 42, 7, 14, 9, 6, 22, 24, 18, 39, 7, 50, 33, 11, 20, 17, 18, 48, 8, 21, 20, 12, 41, 11, 18, 11, 58, 18, 21, 23, 12, 67, 35]
 *     r = await arrGammaInv(arr, 0.5, {
 *         n: 69,
 *         min: 1,
 *         max: 70,
 *     })
 *     console.log(r.inv)
 *     // => 14.297217114904852
 *
 * }
 * test()
 *     .catch((err) => {
 *         console.log(err)
 *     })
 *
 */
async function arrGammaInv(arr, ratio, opt = {}) {

    //check arr
    if (!isarr(arr)) {
        return Promise.reject('arr is not an array')
    }
    if (size(arr) === 0) {
        return Promise.reject('arr is not an effective array')
    }

    //check ratio
    if (!isnum(ratio)) {
        return Promise.reject(`ratio[${ratio}] is not a number`)
    }
    ratio = cdbl(ratio)
    if (ratio < 0) {
        return Promise.reject(`ratio[${ratio}] < 0`)
    }
    if (ratio > 1) {
        return Promise.reject(`ratio[${ratio}] > 1`)
    }

    //bin_n
    let bin_n = get(opt, 'n')
    if (!ispint(bin_n)) {
        bin_n = 30
    }
    bin_n = cint(bin_n)

    //bin_min
    let bin_min = get(opt, 'min', null)

    //bin_max
    let bin_max = get(opt, 'max', null)

    //arrGammaFit
    let rf = await arrGammaFit(arr, {
        n: bin_n,
        min: bin_min,
        max: bin_max,
    })
    // => {
    //   shape,
    //   scale,
    //   arrPdf: rstPdf,
    //   arrCounts: rstCounts,
    //   dx,
    //   bs
    // }

    //jt.gamma.inv
    let r = jt.gamma.inv(ratio, rf.shape, rf.scale)

    return {
        inv: r,
        ...rf,
    }
}


export default arrGammaInv