8 lines
237 B
Clojure
8 lines
237 B
Clojure
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(defn entropy [s]
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(let [len (count s), log-2 (Math/log 2)]
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(->> (frequencies s)
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(map (fn [[_ v]]
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(let [rf (/ v len)]
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(-> (Math/log rf) (/ log-2) (* rf) Math/abs))))
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(reduce +))))
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