> I'm a Clojure newbie trying to the following simple task:
>
> Given a list of maps of the followign format: ({"Type" "A", "Value"
> "5"} {"Type" "B", "Value" "4"} {"Type" "A", "Value" "7.2"} {"Type"
> "A", "Value" "25.4"} {"Type" "B", "Value" "2.982"})
>
> I want to compute a list of maps such that each type appears once in
> the list and the value of the type is the sum of the values, so that
> in the example it would be:
>
> ({"Type", "A", "Value", "37.6"} {"Type", "B", "Value", "6.982"})
>
> Any ideas?
I might write it like this -
(defn sum-by-type [coll]
(for [[k v] (group-by #(% "Type") coll)]
{"Type" k "Value" (apply + (map (comp #(Float/parseFloat %)
#(% "Value")) v))}))
Regards,
BG
--
Baishampayan Ghose
b.ghose at gmail.com
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