obs-transitions.clj

(defn obs-transitions 
  "if we set word to tag, we update the transition tag counts
  from all context usages of word by weight amount"
  [trans-distrs type-assigns word-info tag weight] 
  (reduce
    (fn [res [[before after] count]]
      (let [type-assigns (assoc type-assigns (:word word-info) tag)
            before-tag (type-assigns before)
            after-tag (type-assigns after)]          
         (-> res
                ;; Observe P(tag | tag-assign(before))
                (update-in [before-tag] observe tag (* count weight))
                ;; Observe P(tag-assign(after) | tag)
                (update-in [tag] observe after-tag (* count weight)))))
    trans-distrs      
    (-> word-info :contexts :counts)))