From 39c264bbafc10ad9997c21ae36995ab179d8d2b9 Mon Sep 17 00:00:00 2001
From: rsiddharth <s@ricketyspace.net>
Date: Sun, 24 Sep 2017 02:29:51 +0000
Subject: net: Add (net ricketyspace sicp one twenty nine)

---
 net/ricketyspace/sicp/one/twentynine.scm | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 net/ricketyspace/sicp/one/twentynine.scm

(limited to 'net')

diff --git a/net/ricketyspace/sicp/one/twentynine.scm b/net/ricketyspace/sicp/one/twentynine.scm
new file mode 100644
index 0000000..1dfdc45
--- /dev/null
+++ b/net/ricketyspace/sicp/one/twentynine.scm
@@ -0,0 +1,25 @@
+;;;; Under Creative Commons Attribution-ShareAlike 4.0
+;;;; International. See
+;;;; <https://creativecommons.org/licenses/by-sa/4.0/>.
+
+(define-module (net ricketyspace sicp one twentynine)
+  #:export (simpsons))
+
+(define (sum term a next b)
+  (if (> a b)
+      0
+      (+ (term a)
+         (sum term (next a) next b))))
+
+(define (simpsons f a b n)
+  (let* ((h (/ (- b a) (* 1.0 n)))
+         (y (lambda (k) (+ a (* k h))))
+         (ce (lambda (k) ;coefficient
+               (cond ((or (= k 0) (= k n)) 1)
+                     ((even? k) 2)
+                     (else 4))))
+         (term (lambda (k)
+                 (* (ce k) (f (y k)))))
+         (next (lambda (k) (1+ k))))
+    (* (/ h 3.0)
+       (sum term 0 next n))))
-- 
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