Really randomized numbers

[silent stirrup]

I've heard that math.random, or even the PC's itself are bad in generating random numbers. Any way to make the chances more "real"/fair?

[thin hawk]

https://en.wikipedia.org/wiki/Lavarand

[acoustic pumice]

No unless u wanna rent some CUDA servers

[bronze sage]

Random.org

[brisk sun]

u can create your own pseudo random generator, basically you have to find an algorithm that takes a number, and returns a serial of other numbers between 0 and RAND_MAX (which is the int limit 0x7FFFFFFF)

for example, using the number 0 you need to generate random numbers like
577655601
1248161417
192959563
(this is what the C language generates with seed 0)

so you will have to create your own srand and rand function in lua

[silent stirrup]

Something like:
Number = 1
Math.random(1,10)
↑↑10x↑↑
If Number is in the Math.random then do something?

*yes I know it's not lua

Just a half code half english explanation of what I meant

[silent stirrup]

What is srand 😭😭😭

[brisk sun]

well no since here you use Math.random

[brisk sun]

its for setting a seed, in lua, its ```lua
math.randomseed(0)

[silent stirrup]

Ohhh... Well haven't learned .randomseed yet.

[brisk sun]

well randomness works from a seed

and its the seed that is random

math.randomseed(0)
print(math.random())

this will always be the same number

and i can guess it

[silent stirrup]

So wait

How can it be random then?

If it's always the same

[brisk sun]

because the seed (here the seed is 0) changes

it changes using os.clock()

look

[brisk sun]

;compile

[fleet ferry]

Program Output

0.24691184196099

paulogarithm | lua | lua-5.4.3 | wandbox.org

[brisk sun]

what if i do it again

[brisk sun]

;compile

[fleet ferry]

Program Output

0.24691184196099

paulogarithm | lua | lua-5.4.3 | wandbox.org

[brisk sun]

its the same !

[silent stirrup]

It's the same

Yeah

[brisk sun]

yep

now

math.randomseed(math.floor(os.clock()))
print(math.random())

[brisk sun]

;compile

[fleet ferry]

Program Output

/opt/wandbox/lua-5.4.3/bin/lua: prog.lua:1: bad argument #1 to 'randomseed' (number has no integer representation)
stack traceback:
[C]: in function 'math.randomseed'
prog.lua:1: in main chunk
[C]: in ?

paulogarithm | lua | lua-5.4.3 | wandbox.org

[brisk sun]

woops

[silent stirrup]

Maybe randomseed is just for roblox?

[brisk sun]

;compile

[fleet ferry]

Program Output

0.24691184196099

paulogarithm | lua | lua-5.4.3 | wandbox.org

[silent stirrup]

So normal lua doesn't have this keyword/command?

[brisk sun]

nope

[silent stirrup]

Oh ok

[brisk sun]

;compile

[fleet ferry]

Program Output

0.24691184196099

paulogarithm | lua | lua-5.4.3 | wandbox.org

[brisk sun]

its the same

because

os.clock will be 0

[silent stirrup]

So when os.clock changes

The seed changes

And the numbers change?

[brisk sun]

it doesnt really changes

os.clock is from where your script started

and its mostly 0

now check this

local t = os.time()
print(t)
math.randomseed(t)
print(math.random())

[brisk sun]

;compile

[fleet ferry]

Program Output

1721493051
0.61925528208814

paulogarithm | lua | lua-5.4.3 | wandbox.org

[brisk sun]

0.61 ?

[brisk sun]

;compile

[fleet ferry]

Program Output

1721493061
0.34762780932669

paulogarithm | lua | lua-5.4.3 | wandbox.org

[brisk sun]

wow its random !

because

os.time changes every seconds

and rand generates a pseudo number from the seed

here the seed is 1721493061

so the first rand will be 0.34762780932669

and we can try it out !

math.randomseed(1721493061)
print(math.random())

it will be 0.3476...

[brisk sun]

;compile

[fleet ferry]

Program Output

0.34762780932669

paulogarithm | lua | lua-5.4.3 | wandbox.org

[brisk sun]

do you understand @silent stirrup ?

[silent stirrup]

It's the same, so the "randomeiness" is in the random os.time?

That changes

And generates new numbers every time

What is os.time?

[brisk sun]

its the number of seconds since epoch

like since the January first of 1970

[brisk sun]

os.time is not random

[silent stirrup]

I mean sorry yeah

It changes

[brisk sun]

basically, randomness is generating non-sence numbers from other numbers

[silent stirrup]

And by that change it makes random numbers

[brisk sun]

like 1 will give 817926862, 2 will give 65237653, 3 will give 879873111 etc...

[brisk sun]

yes

but if you know the algorithm

well you can predict random

[brisk sun]

but you cant predict using lavarand

thats true life random events you can observe

[silent stirrup]

But it's still better than math.random? And other than the fact one can predict it, if there was a 10% chance, would it be really 10%? Or 5%? Or maybe anything between 5 and 15%?

[brisk sun]

here is another example, like imagine you have a plant at your house. Each day you will look how much it groth right ?

so day one you will have 0.0000186771001cm lets say you mesure in millimetters, 0,000186, and you multiply by 10000 so you have 1.86771001

then you take the square of this number (which is 3.48834068145) and then you only take the 7 digits after multiplying by 1000 -> 3406814 and then you nand it by the actual number but with the same number of digits less one so

>>> ~(3406814 & 186771)  
-186771

then you have your random number

like the next day for example it will grow 0,000186771130mm which is almost the same
but if we do the same steps

1. multiply = 1.86771130
2. taking square = 3.48834550015
3. multiply again = 3488.34550015
4. take the 7 number = 3455001
5. nand it = ~(3455001 & 1867711)

you came up with a really different number -1325082

[silent stirrup]

So os.time is the same?

Like a plant that grows (a little) every second, and by a little difference (as a seed) you get a totally different number than the last one?

[brisk sun]

no

os.time will just give you the number of seconds

which are 1, 2, 3 ...

[brisk sun]

this algorithm is what math.randomseed does

[silent stirrup]

But will generate random numbers , rig.. oh wait yeah no wait

[brisk sun]

here its my algorithm i did to show you

[silent stirrup]

By os.time I meant

Uhh where it is

I meant the whole algorithm with math.rabdom included

[brisk sun]

well instead of taking my little plant growth, it will take the actual seconds

[silent stirrup]

This

[brisk sun]

yes

[silent stirrup]

Yeah sorry I meant the whole script not only the os.time

[brisk sun]

it will apply an algorithm in the seconds, and then you will have pseudo random

[silent stirrup]

And this is random

[brisk sun]

this is the actual random

[brisk sun]

well its not fully random because if i know the seconds, i can predict the result

[silent stirrup]

Yeah, that's true. But it's still better than math.random, ight?

[brisk sun]

like example

here its 18h51 in france

when it will hit 19h00 (5pm) the os.time will be 1721494800

> math.randomseed(1721494800)
> print(math.random())
0.98815881832331

so if at 5pm 0m 0s in this specific day i do ;compile, it should give me 0.9881

math.randomseed(1721494800)
print(math.random())

[brisk sun]

;compile

[fleet ferry]

Program Output

0.85750753865207

paulogarithm | lua | lua-5.4.3 | wandbox.org

[brisk sun]

well it should give me this number (because its another algorithm than mine)

so you can try

me i will go back to eat

but as you can see its not really random

true randoms are lavalamps or my little plant

since you dont really know how much it will growth with the exact number

[silent stirrup]

Thank you for explaining me that.

Idk how come, but if I want to know a simple thing like for instance right now - is there a better substitute for math.random, I discover that:

• something like os.time exists
  I am witnessing some hardcore math going on here, and on an example of a plant and a PC I now know that PC isn't fully random.

How do my simple questions (at least that's what I think when I ask them) give complicated anwsers, almost always...