(do
  ;; Simple Moving Average O(1)
  (def SMA (fn [len]
    (do
      (def s (Series len))
      (def sum 0.0)
      (fn [val]
        (do
          (if (>= (count s) len)
            (set sum (- sum (get_item s (- len 1))))
            (nop))
          (push s val)
          (set sum (+ sum val))
          (/ sum (count s)))))))

  ;; Weighted Moving Average
  (def WMA (fn [len]
    (do
      (def s (Series len))
      (def weight_sum (/ (* len (+ len 1)) 2))
      (fn [val]
        (do
          (push s val)
          (def current_sum 0.0)
          (def i 0)
          (while (< i (count s))
            (do
              (set current_sum (+ current_sum (* (get_item s i) (- len i))))
              (set i (+ i 1))))
          (/ current_sum weight_sum)))))))