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Google Sheets NORMDIST( x, mean, standard deviation, cumulative T/F) to JavaScript

Google Sheets has the NORMDIST( x, mean, standard deviation, cumulative T/F) function. I have not been able to find something equivalent in JavaScript. The examples I've found do not allow for all the variables that are in the Google function or I don't have the understanding to implement them.
I am trying to write a reiterative JavaScript function to replace a set of reiterative Google Sheets calculations and need something like this;
x = NORMDIST(x,0,1, TRUE);
y = NORMDIST(x,0,1, FALSE);

At a high-level, there's two things that the NORMDIST function can do: calculate the Normal Distribution's PDF when false is supplied as the last parameter and CDF when true is supplied.
The PDF part is easy: just follow the formula given on Wikipedia for Normal Distribution.
The CDF part is less trivial as it's a non-elementary integral. Your best shot is to find some open-source implementation and translate it into JS. (Preferably a non-iterative one.) It won't be 100% exact due to roundoff errors, but it can get you extremely close. I found one here.
Here's what I came up with:
function _getNDistPDF(x, mean, stdev)
{
const sqrt2PI = Math.SQRT2 * Math.sqrt(Math.PI);
let frac = (x - mean) / stdev;
return Math.exp(-.5 * frac * frac) / (sqrt2PI * stdev);
}
// Adapted from https://people.sc.fsu.edu/~jburkardt/c_src/asa066/alnorm.c
function _getNDistCDF(x, mean, stdev)
{
const a1 = 5.75885480458;
const a2 = 2.62433121679;
const a3 = 5.92885724438;
const b1 = -29.8213557807;
const b2 = 48.6959930692;
const c1 = -0.000000038052;
const c2 = 0.000398064794;
const c3 = -0.151679116635;
const c4 = 4.8385912808;
const c5 = 0.742380924027;
const c6 = 3.99019417011;
const con = 1.28;
const d1 = 1.00000615302;
const d2 = 1.98615381364;
const d3 = 5.29330324926;
const d4 = -15.1508972451;
const d5 = 30.789933034;
const ltone = 7.0;
const p = 0.398942280444;
const q = 0.39990348504;
const r = 0.398942280385;
const utzero = 18.66;
let up = false;
let value;
let y;
// For non-standard NDist
let z = (x - mean) / stdev;
if (z < 0)
{
up = true;
z = -z;
}
if (ltone < z && (!up || utzero < z))
{
value = !up * 1;
return value;
}
y = 0.5 * z * z;
if (z <= con)
{
value = 0.5 - z * (p - q * y
/ (y + a1 + b1
/ (y + a2 + b2
/ (y + a3))));
}
else
{
value = r * Math.exp(-y)
/ (z + c1 + d1
/ (z + c2 + d2
/ (z + c3 + d3
/ (z + c4 + d4
/ (z + c5 + d5
/ (z + c6))))));
}
if (!up)
value = 1 - value;
return value;
}
function NDistJS(x, mean, stdev, cumulative)
{
return cumulative
? _getNDistCDF(x, mean, stdev)
: _getNDistPDF(x, mean, stdev);
}
This gives you a function NDistJS that takes the exact same parameters as NORMDIST.
The PDF is 100% accurate to the Sheets formula.
The CDF is 99.9999992% accurate to the Sheets formula for (x=1, m=0, s=1).

Javascript Maths Node Red Thermistor Function

have node-red running with arduino analogue output through serial to pi, where I'm collecting thermistor data as a msg payload on change.
Trying to turn the Arduino signal into a Temperature - it's the most common 10K enamelised thermistor that adafruit sell. So quite useful code.
The issue is that I am a total noob at JS.
Here's my code so far - using a function node - and trying to replicate the steinhart equation (https://learn.adafruit.com/thermistor/using-a-thermistor)
var input = { payload: msg.payload };
var R0 = 10000;
var R = R0 / ((1023 / input)-1);
var T0 = 273 + 25;
var B = 3950;
var T = 1 / ( (1/T0) + (1/B) * Math.log(R/R0) );
return T;

i am not sure whether will msg.payload will return number in an actual datatype "Number" meaning or a string that will be a numeric, but something like this should take care of any anomalies when trying to divide strings
var numInput = Number(msg.payload);
var R0 = 10000;
var R = R0 / ((1023 / input)-1);
var T0 = 273 + 25;
var B = 3950;
var T = 1 / ( (1/T0) + (1/B) * Math.log(R/R0) );
return T;
EDIT: this should fix the errors:
var numInput = Number(msg.payload);
var R0 = 10000;
var R = R0 / ((1023 / numInput)-1);
var T0 = 273 + 25;
var B = 3950;
var T = 1 / ( (1/T0) + (1/B) * Math.log(R/R0) );
msg.payload = T;
return msg;

generate 4 digit random number using substring

I am trying to execute below code:
var a = Math.floor(100000 + Math.random() * 900000);
a = a.substring(-2);
I am getting error like undefined is not a function at line 2, but when I try to do alert(a), it has something. What is wrong here?

That's because a is a number, not a string. What you probably want to do is something like this:
var val = Math.floor(1000 + Math.random() * 9000);
console.log(val);
Math.random() will generate a floating point number in the range [0, 1) (this is not a typo, it is standard mathematical notation to show that 1 is excluded from the range).
Multiplying by 9000 results in a range of [0, 9000).
Adding 1000 results in a range of [1000, 10000).
Flooring chops off the decimal value to give you an integer. Note that it does not round.
General Case
If you want to generate an integer in the range [x, y), you can use the following code:
Math.floor(x + (y - x) * Math.random());

This will generate 4-digit random number (0000-9999) using substring:
var seq = (Math.floor(Math.random() * 10000) + 10000).toString().substring(1);
console.log(seq);

I adapted Balajis to make it immutable and functional.
Because this doesn't use math you can use alphanumeric, emojis, very long pins etc
const getRandomPin = (chars, len)=>[...Array(len)].map(
(i)=>chars[Math.floor(Math.random()*chars.length)]
).join('');
//use it like this
getRandomPin('0123456789',4);

$( document ).ready(function() {
var a = Math.floor(100000 + Math.random() * 900000);
a = String(a);
a = a.substring(0,4);
alert( "valor:" +a );
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>

Your a is a number. To be able to use the substring function, it has to be a string first, try
var a = (Math.floor(100000 + Math.random() * 900000)).toString();
a = a.substring(-2);

You can get 4-digit this way .substring(startIndex, length), which would be in your case .substring(0, 4). To be able to use .substring() you will need to convert a to string by using .toString(). At the end, you can convert the resulting output into integer by using parseInt :
var a = Math.floor(100000 + Math.random() * 900000)
a = a.toString().substring(0, 4);
a = parseInt(a);
alert(a);
https://jsfiddle.net/v7dswkjf/

The problem is that a is a number. You cannot apply substring to a number so you have to convert the number to a string and then apply the function.
DEMO: https://jsfiddle.net/L0dba54m/
var a = Math.floor(100000 + Math.random() * 900000);
a = a.toString();
a = a.substring(-2);

$(document).ready(function() {
var a = Math.floor((Math.random() * 9999) + 999);
a = String(a);
a = a.substring(0, 4);
});

// It Will Generate Random 5 digit Number & Char
const char = '1234567890abcdefghijklmnopqrstuvwxyz'; //Random Generate Every Time From This Given Char
const length = 5;
let randomvalue = '';
for ( let i = 0; i < length; i++) {
const value = Math.floor(Math.random() * char.length);
randomvalue += char.substring(value, value + 1).toUpperCase();
}
console.log(randomvalue);

function getPin() {
let pin = Math.round(Math.random() * 10000);
let pinStr = pin + '';
// make sure that number is 4 digit
if (pinStr.length == 4) {
return pinStr;
} else {
return getPin();
}
}
let number = getPin();

Just pass Length of to number that need to be generated
await this.randomInteger(4);
async randomInteger(number) {
let length = parseInt(number);
let string:string = number.toString();
let min = 1* parseInt( string.padEnd(length,"0") ) ;
let max = parseInt( string.padEnd(length,"9") );
return Math.floor(
Math.random() * (max - min + 1) + min
)
}

I've created this function where you can defined the size of the OTP(One Time Password):
generateOtp = function (size) {
const zeros = '0'.repeat(size - 1);
const x = parseFloat('1' + zeros);
const y = parseFloat('9' + zeros);
const confirmationCode = String(Math.floor(x + Math.random() * y));
return confirmationCode;
}
How to use:
generateOtp(4)
generateOtp(5)
To avoid overflow, you can validate the size parameter to your case.

Numbers don't have substring method. For example:
let txt = "123456"; // Works, Cause that's a string.
let num = 123456; // Won't Work, Cause that's a number..
// let res = txt.substring(0, 3); // Works: 123
let res = num.substring(0, 3); // Throws Uncaught TypeError.
console.log(res); // Error
For Generating random 4 digit number, you can utilize Math.random()
For Example:
let randNum = (1000 + Math.random() * 9000).toFixed(0);
console.log(randNum);

This is quite simple
const arr = ["one", "Two", "Three"]
const randomNum = arr[Math.floor(Math.random() * arr.length)];

export const createOtp = (): number => {
Number(Math.floor(1000 + Math.random() * 9000).toString());
}

decimal value addition not working in javascript

function sum() {
a = Number(document.getElementById("rate_ts").value);
b = Number(document.getElementById("discount").value);
c = a - (Number(a) * Number(b) / 100);
d = Number(document.getElementById("ocharge").value) + c + Number(document.getElementById("pay_amt").value);
tax = (Number(a) * Number(12.36) / 100);
e = tax + d;
document.getElementById("net_amt").value = e;
}
this code is not working right......i want to add tax and for that i have given 12.36 but it is not returning anything..plz help

parseFloat()
Summary
The parseFloat() function parses a string argument and returns a
floating point number.
$('#three').click(function (e) {
a = parseFloat(document.getElementById("rate_ts").value);
b = parseFloat(document.getElementById("discount").value);
console.log(a+' | '+b);
});
WORKING DEMO

Try This,
function sum() {
a = parseFloat(document.getElementById("rate_ts").value);
b = parseFloat(document.getElementById("discount").value);
c = a - (a * b / 100);
d = parseFloat(document.getElementById("ocharge").value) + c + parseFloat(document.getElementById("pay_amt").value);
tax = a * 12.36 / 100;
e = tax + d;
document.getElementById("net_amt").value = e.toFixed(2);
}
If you want only two decimal point value then use number.toFixed(2)
Working Example

Javascript Split String Without Separator

Basically, I have a string of unknown numbers (determined by user input + my own math), and I need to split this string into 3 parts.
For example, I may have "1273498". I need to split it at the two characters, and the 3rd and 4th from the RIGHT, like so:
127
34
98
Another example: 1234567890 would need to be:
123456
78
90
Currently, I am accomplishing it this way:
// get first input box value
var depositgold = document.getElementById('v-gold').value;
// set it to 0 if it's empty
if(depositgold == null || depositgold == '')
depositgold = 0;
// second input box value
var depositsilver = document.getElementById('v-silver').value;
if(depositsilver == null || depositsilver == '')
depositsilver = 0;
// third input box value
var depositcopper = document.getElementById('v-copper').value;
if(depositcopper == null || depositcopper == '')
depositcopper = 0;
// combine the 3 input box values (adding dec to make split easier)
var depositnums = depositgold + '.' + depositsilver + depositcopper;
// do some math on our new value, then split it at out dec
var deposit12 = (0.15 * depositnums).toFixed(4).split(".");
// split the last part of the above split into 4 characters
var result12 = deposit12[1].split("", 3);
// keep the first part of out dec split
var deposit12gold = deposit12[0];
// combine the second part split results into paired numbers
var deposit12silver = result12[0] + result12[1];
var deposit12copper = result12[2] + result12[3];
// repeat the above process
var deposit24 = (0.30 * depositnums).toFixed(4).split(".");
var result24 = deposit24[1].split("", 3);
var deposit24gold = deposit24[0];
var deposit24silver = result24[0] + result24[1];
var deposit24copper = result24[2] + result24[3];
var deposit48 = (0.60 * depositnums).toFixed(4).split(".");
var result48 = deposit48[1].split("", 3);
var deposit48gold = deposit48[0];
var deposit48silver = result48[0] + result48[1];
var deposit48copper = result48[2] + result48[3];
I know there must be a much better (and more sane) way of accomplishing the above - I need to do it several more times for this project, and I'm certainly not looking forward to continuing to do it this way.
I am new to JS and programming, so laugh away, just try not to laugh too hard ;)

Try something along these lines:
var str = "123412341";
var matches = str.match(/(.+?)?(.{2})?(.{2})?$/);
// matches[1] = 12341
// matches[2] = 23
// matches[3] = 41
You may want to modify the RegEx depending on your input, currently all groups are optional.

Just use the substring method
var number = 123456789;
var one = number.substring( 0, number.length - 4 );
var two = number.substring( number.length -4, number.length - 2);
var three = number.substring( number.length - 2 );

Use the substr() method for this:
var L = mystring.length
var part1 = mystring.substr(0,L-4);
var part2 = mystring.substr(L-4,2);
var part3 = mystring.substr(L-2,2);

('1234'+'56'+'78').match(/(\d*)(\d\d)(\d\d)/)
["12345678", "1234", "56", "78"]

var number = 1234567890;
number = number.toString();
var a = number.substr(0, number.length - 4),
b = number.substr(-2),
c = number.substr(number.length - 4, 2);
console.log(a, b, c);
jsFiddle.
Output
123456 90 78

here is a function i made:
/**
* #param num A number to split like 382203849238
* #return Returns an array of size 3, where index 0 = 38220384, index 1 = 92, index 2 = 38 based on the example above
*/
function splitNumbers(num) {
var num = (typeof num == 'string' || typeof num == 'String') ? parseInt(num) : num,
rem = num % 10000;
return [Math.floor(num / 10000), Math.floor(rem / 100), rem % 100];
}

// Function to parse code in 3 parts
function parse_code_Split (code)
{
var len = code.length;
var divisor = (len / 3) >> 0; // get whole number
console.log(divisor);
var stringReg = "";
var regexp = ".{1," + divisor + "}";
try{
stringReg = new RegExp(regexp,"g");
}catch(Error){
window.console.log(Error.message);
}
codeSplit = code.match(stringReg);
// window.console.log(" codeSplit[0] " + codeSplit[0]);
// window.console.log(" codeSplit[1] " + codeSplit[1]);
// window.console.log(" codeSplit[2] " + codeSplit[2]);
// window.console.log(" codeSplit[3] " + codeSplit[3]); // remainder
return codeSplit;
}