From 71b1de4198dad80ffc8755c34aa48a39ef512226 Mon Sep 17 00:00:00 2001
From: rsiddharth <s@ricketyspace.net>
Date: Sat, 14 Oct 2017 03:33:06 +0000
Subject: (net ricketyspace sicp one thirtyone): Simplify pi functions.
* net/ricketyspace/sicp/one/thirtyone.scm
(pi, pi-iter): Update functions.
---
net/ricketyspace/sicp/one/thirtyone.scm | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
(limited to 'net')
diff --git a/net/ricketyspace/sicp/one/thirtyone.scm b/net/ricketyspace/sicp/one/thirtyone.scm
index f84f637..558361e 100644
--- a/net/ricketyspace/sicp/one/thirtyone.scm
+++ b/net/ricketyspace/sicp/one/thirtyone.scm
@@ -29,18 +29,18 @@
(product-iter term 1 next n)))
(define (pi precision)
- (let* ((n (lambda (x) (* (+ (quotient x 2) 1) 2))) ; numerator of term.
- (d (lambda (x) (+ (* (quotient (1+ x) 2) 2) 1))) ; denominator of term.
- (term (lambda (x) (/ (* (n x) 1.0) (* (d x) 1.0))))
+ (let* ((n (lambda (x) (if (even? x) (+ x 2) (+ x 1)))) ; numerator of term.
+ (d (lambda (x) (if (even? x) (+ x 1) (+ x 2)))) ; denominator of term.
+ (term (lambda (x) (/ (n x) (d x))))
(next (lambda (x) (1+ x))))
- (* (product term 1 next precision) 4)))
+ (* (product term 1.0 next precision) 4)))
(define (pi-iter precision)
- (let* ((n (lambda (x) (* (+ (quotient x 2) 1) 2))) ; numerator of term.
- (d (lambda (x) (+ (* (quotient (1+ x) 2) 2) 1))) ; denominator of term.
- (term (lambda (x) (/ (* (n x) 1.0) (* (d x) 1.0))))
+ (let* ((n (lambda (x) (if (even? x) (+ x 2) (+ x 1)))) ; numerator of term.
+ (d (lambda (x) (if (even? x) (+ x 1) (+ x 2)))) ; denominator of term.
+ (term (lambda (x) (/ (n x) (d x))))
(next (lambda (x) (1+ x))))
- (* (product-iter term 1 next precision) 4)))
+ (* (product-iter term 1.0 next precision) 4)))
;;; Guile REPL
--
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