Question

Was thinking I could test the various answers I got in my question about an algorithm for collapsing ranges. So I was thinking I should create a method that creates a whole bunch of ranges and see how the various methods handles it.

But when it comes to generating random stuff I am not very good. I created something like this:

    private static IEnumerable<Range<int>> GenerateRanges()
    {
        var r = new Random();
        var n = 10000;
        while(--n >= 0)
        {
            var start = r.Next(10000);
            var end = r.Next(10000);
            if (end < start)
                Swap(ref start, ref end);
            yield return Range.Create(start, end);
        }
    }

This creates a lot of ranges of course, but they do not give particularly interesting results since I always end up with only one range after collapsing them. How can I create more interesting ranges?

Answer 1

private static IEnumerable<Range<int>> GenerateRanges(int amount, int max, float density, int seed)
{
    var r = new Random(seed);
    var commonLength = max * density / amount; // edited
    var maxLength = commonLength * 2;
    while(--amount >= 0)
    {
        var length = r.Next(maxLength);
        var start = r.Next(max - length);
        var end = start + length;
        yield return Range.Create(start, end);
    }
}

Usage could be: GenerateRanges(1000, 10000, 1.0, someTestSeed)
or could be: GenerateRanges(1000, 10000, .5, someTestSeed) for less overlaps