CODEWITHSUNDEEP
haskellclojure
user1002430
user1002430

Reputation:

Clojure equivalent of this Haskell Moving Average Function?

Attempting to understand the differences between Clojure and Haskell. I have the following code which calculates the moving average of a time-series list of numbers:

movavg n []     = []
movavg n (x:xs) = map (/ n') sums
    where
        sums = scanl (+) (n' * x) $ zipWith (-) xs (replicate n x ++ xs)
        n'   = fromIntegral n

What would be the idiomatic version of this in Clojure?

Upvotes: 3

Views: 537

Answers (1)

Rörd
Rörd

Reputation: 6681

I don't see why a very literal translation of this shouldn't be idiomatic, i.e.:

(defn movavg [n coll]
  (when-let [[x & xs] (seq coll)]
    (map #(/ % n)
         (reductions + (* n x)
                     (map - xs (concat (repeat n x) xs))))))

Particularly code with a lot of sequence functions has always the potential to be very close to Haskell since they're lazy.

Edit: Shortened code according to Justin Kramer's suggestion.

Upvotes: 4

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