MatricesInClojure

Context : ClojureLanguage

Via RosettaCode

(defn transpose [s] (apply map vector s))
(defn nested-for [f x y]   (map (fn [a]     (map (fn [b]       (f a b)) y))   x))
(defn matrix-mult [a b]   (nested-for (fn [x y]                (reduce + (map * x y))) a (transpose b)))
(def ma 1 1 1 1] [2 4 8 16] [3 9 27 81] [4 16 64 256) (def mb 4 -3 4/3 -1/4] [-13/3 19/4 -7/3 11/24] [3/2 -2 7/6 -1/4] [-1/6 1/4 -1/6 1/24)

Output:

=> (matrix-mult ma mb) ((1 0 0 0) (0 1 0 0) (0 0 1 0) (0 0 0 1))