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    Function which returns true with a given probability


    I need to create a function which returns true with a given probability. For example:

    foo(.1) returns true with probability .1

    Could someone provide either a ruby implementation or a generic way to do this?
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    rebel with a cause
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    Code:
    public boolean foo(double probability) {
        return true;
    }


    Seriously, You've got to specify some more logical requirements than that.
    Dear God. What is it like in your funny little brains? It must be so boring.
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    I've said plenty. The technical term for what I have described is weighted random selection. In this case, the selection is between two elements: true and false. The probability p, given as an argument, is the weight assigned to true, and therefore the weight assigned to false is 1-p.

    I ended up finding a Ruby implementation of weighted random selection that works for any number of elements; using this, I wrote my function.
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    Its one of those things you have to read twice. Trust me, he isn't usually so "out-of-it". Also, welcome to Dev Shed =D
    "Java makes impossible things possible, but makes easy things difficult." - Somebody
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    Its one of those things you have to read twice.
    Agreed. Also, I probably could have done better job explaining what I was looking for.

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    Use a PRNG.

    Say you take a probability out of 100. So for foo(.1), that's really like saying, I have a random number from 1-100. Is it less than 10? A standard PRNG available in most languages gives you a uniform distribution, so the probability is .1 that the number is less than 10. So look up creating random numbers in Ruby.

    Generate random number within a range (something like 1-100, 1-1000). Check if random number is less than probability*range. If it is, return true, otherwise return false.
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