S.O.W - SICPお勉強Wiki

描画結果

2010-07-12T16:28:44+09:00

* Picture Language ---- ** Painter #ref(painter.png) #highlight(scheme){ ;; rate倍に縮小してframeを中心に移動する ; (後でまともにする) (define (reduction-center rate painter) (let ((origin (/ (- 1.0 rate) 2))) (transform-painter painter (make-vect origin origin) (make-vect (+ origin rate) origin) (make-vect origin (+ origin rate))))) (below (beside (reduction-center 0.8 outline) diagonal) (beside diamond wave)) } ** Corner-split #ref(corner4.png) #highlight(scheme){ (corner-split wave 4) } ** Square-limit #ref(squarelimit.png) #highlight(scheme){ (square-limit wave 4) } Ruby-GDでつくってみたけれど, Gauche-GDで作り直したい ** おまけ #ref(hoge2.gif) #highlight(scheme){ ;Gauche-GDにて作成。関数名が適当なのは気にしない (define aho (lambda (x) (corner-split x 3))) (define aho1 (lambda (x) (rotate90 (corner-split x 3)))) (define aho2 (lambda (x) (rotate180 (corner-split x 3)))) (define aho3 (lambda (x) (rotate270 (corner-split x 3)))) (define hoge (square-of-four aho1 aho

Exercises 2.2.4

2010-06-25T14:07:23+09:00

* Chapter 2.2.4 ** Picture Language - [[描画結果]] ---- #pcomment(reply, コメント/2.2.2) ---- ** Exercise 2.44 #highlight(scheme){ (define (align-operator combiner op1 op2) (lambda (painter) (combiner (op1 painter) (op2 painter)))) (define align-vert (align-operator below identity identity)) (define align-horiz (align-operator beside identity identity)) (define (up-split painter n) (if (= n 0) painter (below painter (align-horiz (up-split painter (- n 1)))))) } ---- ** Exercise 2.45 #highlight(scheme){ (define right-split (split beside below)) (define up-split (split below beside)) (define (split align-identity align-splitted) (define (splitter painter n) (if (= n 0) painter (align-identity painter ((align-operator align-splitted) (splitter painter (- n 1)))))) splitter) } ---- * 以降はFrame, Painterの実装について ** Exercise 2.46 #highlight(scheme){ ; vector constructor and selectors ; vector operating procedures (define make-vec

Exercises 2.2.2

2010-05-26T04:33:59+09:00

* Chapter 2.2.2 ---- #pcomment(reply, コメント/2.2.2) ---- ** Exercise 2.24 #highlight(scheme){ (define ans (cons 1 (cons (cons 2 (cons (cons 3 (cons 4 '())) '())) '()))) } ---- ** Exercise 2.25 #highlight(scheme){ (define (pick x ls) (define (sub x ls) (if (null? ls) false (if (pair? ls) (pick x ls) (if (= x ls) true false)))) (if (not (sub x (car ls))) (sub x (cdr ls)) true)) } ---- ** Exercise 2.26 #highlight(scheme){ > (define x (list 1 2 3)) > (define y (list 4 5 6)) > (append x y) (1 2 3 4 5 6) > (cons x y) ((1 2 3) 4 5 6) > (list x y) ((1 2 3) (4 5 6)) } ---- ** Exercise 2.27 #highlight(scheme){ (define (rev ls) (define (it ls re) (if (null? ls) re (it (cdr ls) (cons (car ls) re)))) (it ls '())) (define (d-rev ls) (define (it ls re) (if (null? ls) re (if (pair? (car ls)) (it (cdr ls) (cons (d-rev (car ls)) re)) (it (cdr ls) (cons (car ls) re))))) (it ls '())) } ---- ** Exerci

コメント/2.2 Hierarchical Data and the Closure Property

2010-04-03T16:27:09+09:00

-問題数が多いので分割します - jout 2010-04-03 16:27:09

Exercises 2.2.1

2010-04-03T16:29:35+09:00

* Chapter 2.2.1 ---- #pcomment(reply, コメント/2.2.1) ---- ** Exercise 2.17 #highlight(scheme){ (define (last-pair ls) (if (null? (cdr ls)) (car ls) (last-pair (cdr ls)))) } ---- ** Exercise 2.18 #highlight(scheme){ (define (rev ls) (define (iter ls re) (if (null? (cdr ls)) (cons (car ls) re) (iter (cdr ls) (cons (car ls) re)))) (iter (cdr ls) (cons (car ls) '()))) } ---- ** Exercise 2.19 #highlight(scheme){ (define us-coins (list 50 25 10 5 1)) (define uk-coins (list 100 50 20 10 5 2 1 0.5)) (define (cc amount coin-values) (define (first-denomination coin) (car coin)) (define (no-more? coin) (null? coin)) (define (except-first-denomination coin) (cdr coin)) (cond ((= amount 0) 1) ((or (< amount 0) (no-more? coin-values)) 0) (else (+ (cc amount (except-first-denomination coin-values)) (cc (- amount (first-denomination coin-values)) coin-v

2.2 Hierarchical Data and the Closure Property

2010-06-25T13:57:40+09:00

*Chapter 2.2 **[[Exercises 2.2.1]] **[[Exercises 2.2.2]] **[[Exercises 2.2.4]] **Note #pcomment()

Exercises 2.1

2010-03-09T16:37:24+09:00

* Chapter 2.1 ---- #pcomment(reply,コメント/2.1) ---- **Exercise 2.1 #highlight(scheme){ (define (make-rat n d) (define (cons-rat n d) (let ((g (gcd n d))) (cons (/ n g) (/ d g)))) (if (< (* n d) 0) (cons-rat (- (abs n)) (abs d)) (cons-rat (abs n) (abs d)))) } ---- **Exercise 2.2 #highlight(scheme){ (define (average x y) (/ (+ x y) 2)) (define (make-segment p q) (cons p q)) (define (start-segment seg) (car seg)) (define (end-segment seg) (cdr seg)) (define (make-point x y) (cons x y)) (define (x-point p) (car p)) (define (y-point p) (cdr p)) (define (midpoint-segment s) (let ((p (start-segment s)) (q (end-segment s))) (make-point (average (x-point p) (x-point q)) (average (y-point p) (y-point q))))) } ---- **Exercise 2.3 ---- **Exercise 2.4 #highlight(scheme){ ; cons,car,cdrを手続きで表現する (define (cons2 x y) (lambda (m) (m x y))) (define (car2 z) (z (lambda (a d) a))) (define (cdr2 z) (z (lambda (a d) d))) } ---- **Exercise 2.5

2.1 Introduction to Data Abstraction

2010-03-04T13:15:13+09:00

*Chapter 2.1 **[[Exercises 2.1]] **Note #pcomment()

コメント/1.3 Formulating Abstractions with Higher-Order Procedures

2010-02-24T07:27:04+09:00

-1.3の日本語訳 ttp://www.comp.tmu.ac.jp/morbier/sysa/1.3.html - tar0_t 2010-02-24 07:27:06

Exercises 1.3

2010-03-01T17:37:49+09:00

* Chapter 1.3 ---- **Exercise 1.29 #highlight(,scheme){ (define (simpson f a b n) (if (and (> n 0) (even? n)) (simpson-in f a b (/ (- b a) n)) (simpson f a b (+ n 1)))) (define (simpson-in f a b h) (define (g x) (+ (f x) (* 2 (f (+ x h))))) (define (add-2h x) (+ x h h)) (/ (* h (+ (f a) (f b) (* 4 (f (+ a h))) (* 2 (sum g (add-2h a) add-2h (- b h))))) 3)) } - simpson手続きはnが2以上の偶数になるまで, +1し続ける - sum手続きの中身は, n≧2のとき下のΣの中身と同じ. n=2のときはf(a)+4f(a+h)+f(b)になる. - [[シンプソンの公式>http://ja.wikipedia.org/wiki/%E3%82%B7%E3%83%B3%E3%83%97%E3%82%BD%E3%83%B3%E3%81%AE%E5%85%AC%E5%BC%8F]] #math(100){{ \int_{a}^{b}f \approx \frac{h}{3} \left( f(a) + 4f(a+h) + 2\sum_{k=1}^{n/2-1} \left( f(a+2kh) + 2f\left( a+(2k+1)h \right) \right + f(b) \right) }} #pcomment(reply,コメント/1.29) ---- **Exercise 1.30 #highlight(,scheme){ (define (sum f a next b) (define (iter a result) (if (> a b) result (iter (next a) (+ result (f a))))) (iter a 0)) ; 評価の