import crypto from "crypto"; export const hashString = (string) => crypto.createHash("md5").update(string).digest("hex"); const id = (x) => x; export const transformSliderValueToActualValue = id; export const transformSliderValueToPracticalValue = id; export const _transformSliderValueToActualValue = (value) => 10 ** value; //>= 2 ? Math.round(10 ** value) : Math.round(10 * 10 ** value) / 10 export const toLocale = (x) => Number(x).toLocaleString(); export const truncateValueForDisplay = (value) => { if (value > 10) { return Number(Math.round(value).toPrecision(2)); } else if (value > 1) { return Math.round(value * 10) / 10; } else if (value <= 1) { return value; } }; export const _transformSliderValueToPracticalValue = (value) => truncateValueForDisplay(transformSliderValueToActualValue(value)); export function sleep(ms) { return new Promise((resolve) => setTimeout(resolve, ms)); } export function numToAlphabeticalString(num) { // https://stackoverflow.com/questions/45787459/convert-number-to-alphabet-string-javascript/45787487 num = num + 1; var s = "", t; while (num > 0) { t = (num - 1) % 26; s = String.fromCharCode(65 + t) + s; num = ((num - t) / 26) | 0; } return `#${s}` || undefined; } let topOutAt100AndValidate = (x) => { // return 10; if (x == x) { return x > 99 ? 99 : x < 0 ? 2 : x; } else { return 10; } }; export function formatLargeOrSmall(num) { let result; if (num >= 1) { result = toLocale(truncateValueForDisplay(num)); } else if (num > 0) { let candidateNumSignificantDigits = -Math.floor(Math.log(num) / Math.log(10)) + 1; let numSignificantDigits = topOutAt100AndValidate( candidateNumSignificantDigits ); result = num.toFixed(numSignificantDigits); } else if (-1 < num) { let candidateNumSignificantDigits = -Math.floor(Math.log(Math.abs(num)) / Math.log(10)) + 1; let numSignificantDigits = topOutAt100AndValidate( candidateNumSignificantDigits ); result = num.toFixed(numSignificantDigits); } else if (num <= -1) { result = "-" + toLocale(truncateValueForDisplay(-num)); } else { result = toLocale(num); //return "~0" } console.log(`${num} -> ${result}`); return result; } const firstFewMaxMergeSortSequence = [ 0, 0, 1, 3, 5, 8, 11, 14, 17, 21, 25, 29, 33, 37, 41, 45, 49, 54, 59, 64, 69, 74, 79, 84, 89, 94, 99, 104, 109, 114, 119, 124, 129, 135, 141, 147, 153, 159, 165, 171, 177, 183, 189, 195, 201, 207, 213, 219, 225, 231, 237, 243, 249, 255, 261, 267, 273, 279, 285, ]; export function maxMergeSortSteps(n) { if (n < firstFewMaxMergeSortSequence.length) { return firstFewMaxMergeSortSequence[n]; } else { return ( maxMergeSortSteps(Math.floor(n / 2)) + maxMergeSortSteps(Math.ceil(n / 2)) + n - 1 ); } } export function expectedNumMergeSortSteps(n) { // https://cs.stackexchange.com/questions/82862/expected-number-of-comparisons-in-a-merge-step // n-2 for each step, so (n-2) + (n-2)/2 + (n-2)/4 + ... // ~ 2*(n-2) -1 = 2*n - 3 if (n == 0) { return 0; } else if (n == 1) { return 0; } else if (n == 2) { return 1; } else if (n == 3) { return 2; } else { return ( Math.ceil(n ** 2 / (n + 2)) + expectedNumMergeSortSteps(Math.ceil(n / 2)) ); } } const sum = (arr) => arr.reduce((a, b) => a + b, 0); export const avg = (arr) => sum(arr) / arr.length; export const geomMean = (arr) => { let n = arr.length; let logavg = sum(arr.map((x) => Math.log(x))); // works for low numbers much better let result = Math.exp(logavg / n); return result; }; export const hackyGeomMean = (arr) => { let nonPositiveNumbers = arr.filter((x) => x <= 0); if (nonPositiveNumbers.length == 0) { return geomMean(arr); } else { return avg(arr); } }; export function conservativeNumMergeSortSteps(n) { return Math.ceil((expectedNumMergeSortSteps(n) + maxMergeSortSteps(n)) / 2); } // export const geomMean = (arr) => arr.reduce((a, b) => a * b, 1); // ^ (1 / arr.length); // didn't work so well for low numbers. export const increasingList = (n) => Array.from(Array(n).keys()); function getStdev(arr) { if (Array.isArray(arr) && arr.length > 0) { const n = arr.length; const mean = arr.reduce((a, b) => a + b) / n; return Math.sqrt( arr.map((x) => Math.pow(x - mean, 2)).reduce((a, b) => a + b) / n ); } else { return 0; } } export const getCoefficientOfVariation = (arr) => { let nonPositiveNumbers = arr.filter((x) => x <= 0); if (nonPositiveNumbers.length == 0) { let gm = geomMean(arr); let stdev = getStdev(arr); return stdev / gm; } else { return getStdev(arr) / avg(arr); } };