How to get the randomseed?
According to the wiki, math.randomseed sets the pseudo-random generator to determine the sequence of numbers math.random will generate.
But...
It shows us how to set the seed, but is it possible to get the seed? What use does the math.randomseed argument have (besides passing the timestamp tick), if we can't get the seed of the current environment.
What if I said something like:
for i = 1,5 do
print(math.random(10))
end
And gave an output of:
3
7
5
1
9
Is there a way I could get the random seed from this environment, so I could then pass it as an argument to math.randomseed in another script, so it would generate the same number pattern in that situation?
1 answer
math.randomseed(x) Sets x as the "seed" for the pseudo-random generator: equal seeds produce equal sequences of numbers.
Because you must explicitly set the seed, you could just record the value of x as you set it.
function setRandomSeed(seed)
local seed = seed or tick()
math.randomseed(seed)
return seed
end
As for getting the seed from a list of numbers:
math.random works by applying a series of mathematical operations given a value and a seed in order to generate a seemingly random sequence of numbers. However, in order to retrieve the seed, you would need to know what these operations are in order to complete the inverse operations and retrieve the seed.
I'm sure there is some source code out there somewhere were you could derive a formula to find the seed, but it is much more convenient and efficient to simply record which seed is being used.