babbage-sets.clj

;; Babbage provides some built-in simple accumulators.
user> (use 'babbage.core)
user> (require '[babbage.provided.core :as p])
nil

;; Create several sets of interest.
user> (def mysets 
        (sets  {:firefox? #(-> % :browser (= :firefox))
                :chrome?  #(-> % :browser (= :chrome))
                :ie?      #(-> % :browser #{:ie-7 :ie-8 :ie-9 :ie-10})
                :spent-at-all? #(-> % :spend (> 0))}))

;; Using the result from before, compute the mean of the "spend" field for each set.
user> (->> (all-visitors) :compile-all                         
           (calculate mysets {:spend (stats :spend p/mean)})) 

;; We get back the mean for each set.
user> (->> (all-visitors) :compile-all                         
           (calculate mysets {:spend (stats :spend p/mean)}))
{:all      {:spend {:mean 3.0, :sum 9, :count 3}},
 :firefox? {:spend {:mean 3.0, :sum 9, :count 3}},
 :chrome?  nil,
 :ie?      nil,
 :spent-at-all? {:spend {:mean 4.5, :sum 9, :count 2}}}