26 lines
607 B
Lua
26 lines
607 B
Lua
function getFile (filename)
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local inFile = io.open(filename, "r")
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local fileContent = inFile:read("*all")
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inFile:close()
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return fileContent
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end
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function log2 (x) return math.log(x) / math.log(2) end
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function entropy (X)
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local N, count, sum, i = X:len(), {}, 0
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for char = 1, N do
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i = X:sub(char, char)
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if count[i] then
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count[i] = count[i] + 1
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else
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count[i] = 1
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end
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end
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for n_i, count_i in pairs(count) do
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sum = sum + count_i / N * log2(count_i / N)
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end
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return -sum
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end
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print(entropy(getFile(arg[0])))
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