Does anybody know a faster way to do this?
Each XN in the expression is always the previous X, so just restructure the code to use the previous X rather than creating new ones:
local X = os.time()
local A1 = 710425941047
local B1 = 813633012810
local M1 = 711719770602
function myrandomseed(val)
X = val
end
function myrandom()
X = (A1 * X + B1) % M1
return X
end
Now you can call myrandom
to your heart's content:
for i=1,100 do
print(myrandom())
end
Another way of packaging it, to avoid static scope, would be generating random number generators as closures, which bind to their state variables:
function getrandom(seed)
local X = seed or os.time()
local A1 = 710425941047
local B1 = 813633012810
local M1 = 711719770602
return function()
X = (A1 * X + B1) % M1
return X
end
end
Now you call getrandom
to get a random number generator for a given seed:
local rand = getrandom()
for i=1,100 do
print(rand())
end
I would love to be able to fit it into something along the lines of a: math.randomseed(X[loop count]) local roll=math.random(1,20)
If you're calling randomseed every time you call random, you're not using Lua's (i.e. C's) random number generator at all. You can see why this is true by looking at myrandomseed
above. Why are you funneling your numbers through Lua's random in the first place? Why not just use math.random
and be done with it.
Just make to sure to call math.randomseed
once rather than every time you call math.random
and you'll be fine.
I'm using it to generate random numbers for pieces of track I'm making in a tabletop game. Example hunk of code:
When you see tons of nearly identical code, you should refactor it. When you see variables names like foo1
, foo2
, etc. you're either naming variables poorly or should be using a list. In your case you have a bunch of branches Count == 1
, Count == 2
, etc. when we could be using a list. For instance, this does the same thing as your code:
local trackTypes = { 'Straightaway', 'Curve', 'Hill', 'Water', 'Jump' }
for i=1,S do
local trackTypeIndex = math.random(1, #trackTypes)
local SP = math.random(1, 3)
p(trackTypes[trackTypeIndex]..' of SP '..SP)
end
Note that you can probably guess what trackTypes
is just by reading the variable name. I have no idea what S
and SP
are. They are probably not good names.