spurperl,
I have only briefly read the other replies, but I believe my solution may be unique. If it isn't, then I apologize.

First let me solve your overly simplistic example, then give you the logic behind a more general solution:

For example, I'd like to decide between 0, 1 and 2 randomly, with 0 and 1 having an equal chance to be chosen, and 2 having a chance that is twice higher.

This can be reduced to generating a random number between 1 and 4 and then checking the results.

  • If the number is 1, then choose 0
  • if the number is 2 then choose 1
  • If the number is 3 or 4 then choose 2

    The more general approach to this is to calculate how many elements are required to cover the entire range, and then set up the range logic to check the results.

    I haven't provided any code because it is pretty straight forward, but if you would like to see some code that can generate the weighting dynamically - let me know as it less straight forward (but still not too difficult).

    Hope this helps - L~R

    Update: Just realized this is my 100th post - woo hoo

    In reply to Re: Weighted random numbers generator by Limbic~Region
    in thread Weighted random numbers generator by spurperl

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