What is BigNum?

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#1

Is BigNum something that somehow calculates big numbers that Luau cant? (e.g. 10^40 numbers).
Something like this BigNum ModuleScript.

What’s the official limit that Luau will have trouble calculating? (e.g. 10^23)

How can i bypass 50 digits in number values?
#2

math.huge is the biggest number possible(although it will be named as inf). According to the developer hub, “The maximum numerical value that may be stored is 2^53, or 9,007,199,254,740,992, and the minimum is -9,007,199,254,740,992. It stores up to 15 digits of precision”.

#3

The BigNum module mentioned above could be used to work with numbers outside that limit. There are also libraries like this for other languages like C.

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#4

How come this number is bigger than 2^53? If it can’t store it, it can’t do calculations with it.


local ReplicatedStorage = game:GetService("ReplicatedStorage")
local MoneyLib = require(ReplicatedStorage.MoneyLib)

local function StartOperation()
	local num = 15
	while true do
		num *= 1.15
		print(MoneyLib.DealWithPoints(num), "----------", num)
		if num >= 10 ^ 60 then
			break
		end
		wait(0.1)
	end
end

wait(3)
StartOperation()
-- After a long time...
--[[
 17:26:11.866  424OcD ---------- 4.2472861317277e+59  -  Server - Script:9
  17:26:11.966  488OcD ---------- 4.8843790514868e+59  -  Server - Script:9
  17:26:12.084  561OcD ---------- 5.6170359092098e+59  -  Server - Script:9
  17:26:12.199  645OcD ---------- 6.4595912955913e+59  -  Server - Script:9
  17:26:12.316  742OcD ---------- 7.42852998993e+59  -  Server - Script:9
  17:26:12.433  854OcD ---------- 8.5428094884195e+59  -  Server - Script:9
  17:26:12.549  982OcD ---------- 9.8242309116824e+59  -  Server - Script:9
  17:26:12.649  1.12NvD ---------- 1.1297865548435e+60  -  Server - Script:9
]]--

Edit: I remember getting to something like 10^270 before it started saying it was inf.

Edit2: I prob should’ve used runservice.

#5

Improved version

local ReplicatedStorage = game:GetService("ReplicatedStorage")
local RunService = game:GetService("RunService")
local MoneyLib = require(ReplicatedStorage.MoneyLib)

local function StartOperation()
	local num = 15
	while true do
		num *= 1.15
		print(MoneyLib.DealWithPoints(num), "----------", num)
		if num >= 10 ^ 500 then
			break
		end
		RunService.Heartbeat:Wait()
	end
end

wait(3)
StartOperation()

--[[
 After a long time...
  17:34:49.099  8.7695317786717e+307 ---------- 8.7695317786717e+307  -  Server - Script:10
  17:34:49.113  1.0084961545472e+308 ---------- 1.0084961545472e+308  -  Server - Script:10
  17:34:49.131  1.1597705777293e+308 ---------- 1.1597705777293e+308  -  Server - Script:10
  17:34:49.149  1.3337361643887e+308 ---------- 1.3337361643887e+308  -  Server - Script:10
  17:34:49.164  1.533796589047e+308 ---------- 1.533796589047e+308  -  Server - Script:10
  17:34:49.181  1.7638660774041e+308 ---------- 1.7638660774041e+308  -  Server - Script:10
  17:34:49.197  inf ---------- inf  -  Server - Script:10
]]

Edit: Uh.. Apparently MoneyLib can only go up to 10 ^ 123
#6

The comment in the module explains how it stores big numbers:

--    A Big Number is a table with as many numbers as necessary to represent
--       its value in base 'RADIX'. It has a field 'len' containing the num-
--       ber of such numbers and a field 'signal' that may assume the values
--       '+' and '-'.
#7

IntValues have a cap much lower than NumberValues which can go to 1e+308 or 10^308.

Once you reach past that you will get INF.

I personally don’t recommend BigNum, as it heavily lags with more than a few calculations per second, which is needed. You could also write your own module to get numbers above the 1e+308 cap. I’ve already written such a module, and it has a max of 1e+1e+308.

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#8

Yeah but I was replying to TOP_Crundee123 about that…

#9

I don’t really need to go over 1e300 cap, in fact I only need to go up to 10 ^ 61. I read a post by Kampf that NumberValues started having trouble storing numbers pass 10 ^ 23. I’ll look for the post.

#10

The trouble of storing numbers past 10^23 is a floating point precision error, and it simply means its not as accurate. In the post you mentioned, even though he multiplied by 10, it ended up being something a little wrong.

Once you start hitting that large of numbers, you should have a system to compact it, such as compact notation (1000 to 1k). Those errors won’t even be visible if you do that, and unless you NEED it to be 100% accurate, which normally you don’t, its fine.

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#11

I thought he meant that numbervalues just stopped working because it broke once hitting 10 ^ 23. So I guess I know now.

#12

Nope, just a little inaccurate is all.

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