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added todo for tablex.weighted_random, removed returning the weight value as multi-return wasn't documented and could break in some circumstances
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15
tablex.lua
15
tablex.lua
@ -202,24 +202,29 @@ function tablex.take_random(t, r)
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return table.remove(t, tablex.random_index(t, r))
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end
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--return a random index based on weights provided
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--Example: { 0.3, 1, 6, 0.5 } (3rd index most likely)
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--return a random index based on weights provided (or nil if it's empty)
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-- { 0.3, 1, 6, 0.5 } -> (3rd index most likely)
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-- possible todo:
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-- provide normalisation outside of this function, require normalised weights
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-- provide table of values _and_ weights and return the value
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function tablex.weighted_random(t, r)
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if #t == 0 then
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return nil
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end
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local sum = 0
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for _, weight in ipairs (t) do
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for _, weight in ipairs(t) do
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sum = sum + weight
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end
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local rnd = _random(nil, nil, r) * sum
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sum = 0
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for i, weight in ipairs (t) do
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for i, weight in ipairs(t) do
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sum = sum + weight
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if rnd <= sum then
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return i, weight
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return i
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end
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end
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--shouldn't get here but safety if using a random that returns >= 1
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return #t
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end
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--shuffle the order of a table
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