This is my Clojure solution to Chapter 1, Exercise 44:
(ns sicp.ch1.ex44
(:require [sicp.ch1.ex16 :as ch1-ex16]
[sicp.ch1.ex40 :as ch1-ex40]
[sicp.ch1.ex43 :as ch1-ex43]))
(defn smooth
[f]
#(/ (+ (f (- % ch1-ex40/dx))
(f %)
(f (+ % ch1-ex40/dx)))
3))
(defn n-fold-smooth
[f n]
((ch1-ex43/repeated smooth n) f))
(comment
((smooth ch1-ex16/square) 5) ; => ~25
((n-fold-smooth ch1-ex16/square 2) 5) ; => ~25
#__)
This is my Clojure solution to Chapter 1, Exercise 43:
(ns sicp.ch1.ex43
(:require [sicp.ch1.ex16 :as ch1-ex16]
[sicp.ch1.ex42 :as ch1-ex42]))
(defn repeated
[f n]
(loop [g identity n n]
(if (zero? n)
g
(recur (ch1-ex42/compose f g) (dec n)))))
(comment
((repeated ch1-ex16/square 2) 5) ; => 625
#__)
This is my Clojure solution to Chapter 1, Exercise 42:
(ns sicp.ch1.ex42
(:require [sicp.ch1.ex16 :as ch1-ex16]))
(defn compose
[f g]
#(f (g %))) ; could use comp
(comment
((compose ch1-ex16/square inc) 6)
#__)
This is my Clojure solution to Chapter 1, Exercise 41:
(ns sicp.ch1.ex41)
(defn double-it
[f]
#(f (f %))) ; could use comp
(comment
(((double-it (double-it double-it)) inc) 5) ; => 21
#__)
