[Solved][CharGen]math.random() is not random enough

Question

It seems that all the times i have it run, i am getting a lot of middle numbers. not very many highs or lows.

for example, if i want a random number
between 0-5 i get a lot of 2s and 3s
some 4s and 1s but almost never any 0s or 5s.

Update: still not seeing any range variation after using "java.util.concurrent.ThreadLocalRandom;"

Solution: i needed to tweek the numbers it was randomly generating to extend the range and reduce the offset.

Answer 1

I copied your "Character generator" program, stripped out everything that wasn't a random() call, then calculated the balance of each result over 100,000 iterations (for each category).

After compensating for the "stats retries" (for being too low) -- and just counting retries for 11 -- the output looks fairly balanced, so you might be seeing local effects.

I didn't test for any sort of grouping, but (like flipping tails 100x in a row) an infinite RNG could hang around a place for "as long as it wants", since I think it only has to even out after infinite time. Forcing apparent smoothness in a shorter time is non-random, but it's an interesting idea...

https://code.sololearn.com/cfcWVOC88168/?ref=app

(Percentage totals won't be exactly 100% due to rounding)

Answer 2

I think localRandomThreads would be the 'most random'. Try testing and comparing Math.random to it.

This is the code:

import java.util.concurrent.ThreadLocalRandom;

int randomNum = ThreadLocalRandom.current().nextInt(0, 6);

This should produce a random number from 0-5.

Answer 3

Probably you have to modify the seed like C