Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
小数の丸め誤差の話
Search
circled9
July 26, 2024
Programming
0
120
小数の丸め誤差の話
Niigata5分Tech #10の発表資料です。
https://niigata-5min-tech.connpass.com/event/324842/
circled9
July 26, 2024
Tweet
Share
More Decks by circled9
See All by circled9
キースイッチ入門
circled9
0
69
CloudflareのAI関連の機能さわってみた
circled9
0
530
0.0.0.0 day
circled9
0
94
数値の文字列をパースしよう
circled9
0
200
🔥 Hono v4 やってみた
circled9
1
180
JetBrains AI Assistant を試してみた
circled9
1
490
Fresh
circled9
0
230
React Hooks 勉強会 vol.3
circled9
2
430
JSON.stringify()
circled9
2
480
Other Decks in Programming
See All in Programming
Dissecting and Reconstructing Ruby Syntactic Structures
ydah
1
840
エンジニア向けCursor勉強会 @ SmartHR
yukisnow1823
0
490
実践Webフロントパフォーマンスチューニング
cp20
25
5.7k
AHC045_解説
shun_pi
0
560
REALITY コマンド作成チュートリアル
nishiuriraku
0
110
Fiber Scheduler vs. General-Purpose Parallel Client
hayaokimura
1
110
生成AIを使ったQAアプリケーションの作成 - ハンズオン補足資料
oracle4engineer
PRO
3
250
The Implementations of Advanced LR Parser Algorithm
junk0612
1
390
The Nature of Complexity in John Ousterhout’s Philosophy of Software Design
philipschwarz
PRO
0
130
Bedrock×MCPで社内ブログ執筆文化を育てたい!
har1101
6
1.1k
「影響が少ない」を自分の目でみてみる
o0h
PRO
2
1.2k
監視 やばい
syossan27
11
10k
Featured
See All Featured
Designing for Performance
lara
608
69k
4 Signs Your Business is Dying
shpigford
183
22k
Building Better People: How to give real-time feedback that sticks.
wjessup
367
19k
Writing Fast Ruby
sferik
628
61k
Git: the NoSQL Database
bkeepers
PRO
430
65k
Chrome DevTools: State of the Union 2024 - Debugging React & Beyond
addyosmani
5
560
Speed Design
sergeychernyshev
29
900
実際に使うSQLの書き方 徹底解説 / pgcon21j-tutorial
soudai
178
53k
Product Roadmaps are Hard
iamctodd
PRO
52
11k
Producing Creativity
orderedlist
PRO
344
40k
CSS Pre-Processors: Stylus, Less & Sass
bermonpainter
357
30k
Designing Experiences People Love
moore
141
24k
Transcript
খͷؙΊޡࠩͷ Niigata 5min Tech #10 @circled9 1
ࣗݾհ @circled9 দҪɹਖ਼ࢤ / Matsui Masashi גࣜձࣾϞχΫϧ جຊใٕज़ऀͷࢿ֨͋Γ·͕͢ هԱ͋Γ·ͤΜ 2
ࠓখͷؙΊޡࠩͷΛ͠·͢ 3
Node.js 4
Ͳ͏ͯ͠ʁ • ଟ͘ͷϓϩάϥϛϯάݴޠɺ෦తʹΛೋਐͰѻ͍ͬͯΔ • ेਐͷখΛೋਐʹม͢Δͱޡ͕ࠩੜ͡Δ߹͕͋Δ • Ή͠Ζޡ͕ࠩग़ͳ͍ํ͕গͳ͍ͷͰ...? 5
ेਐͷখΛೋਐͰද͢ͷ͍͠ • ೋਐͷͷNܻ2ͷN-1ͷ 1 1 1 1 = 15 8
4 2 1 • ҰํɺೋਐͷখͷNܻ2ͷϚΠφεN-1ͷ 0. 1 1 1 = 0.5 + 0.25 + 0.125 = 0.875 1 1/2 1/4 1/8 • 2ͷϚΠφεNͷΈ߹ΘͤͰਖ਼֬ʹදݱͰ͖Δʹݶք͕͋Δ 6
Node.js 7
Ͳ͏͢ΕޡࠩΛ͛Δ͔ • খͷܭࢉΛͯ͠େৎͳܕͳͲΛ͏ • খͰͳ͘ͷܭࢉʹ͢Δ 8
খͷܭࢉΛͯ͠େৎͳܕͳͲΛ͏ • C#ͷ߹decimalܕ͕͋Δ • Pythonͷ߹decimalϞδϡʔϧ͕͋Δ • JavaScriptͷ߹big.jsͳͲͷϥΠϒϥϦ͕͋Δ 9
Python 10
খͰͳ͘ͷܭࢉʹ͢Δ • ܭࢉ͢Δલʹʹͯ͠ɺܭࢉޙʹখʹ͢ • ྫ͑100Λ͔͚ͯɺ࠷ޙʹ100ͰׂΔ • ((0.1 * 100) +
(0.2 * 100)) / 100 • ͜ͷ߹ɺܭࢉରͷͷܻΛؾʹ͢Δඞཁ͕͋Δ 11
Node.js 12
·ͱΊ • ଟ͘ͷϓϩάϥϛϯάݴޠͰɺখͷܭࢉͰޡ͕ࠩൃੜ͢Δ • ޡࠩΛग़͞ͳ͍Α͏ʹ͢ΔʹదͳରԠΛ͢Δඞཁ͕͋Δ 13
ଟ͘ͷϓϩάϥϛϯάݴޠʁ 14
খͷܭࢉͰޡࠩͷग़ͳ͍ϓϩάϥϛϯάݴޠ • COBOL • Ada • MSX-BASIC • etc... දݱʹBCDΛ͏ͷ͕ϙΠϯτͬΆ͍
15
BCD • Binary-Coded DecimalɺೋਐԽेਐ • ೋਐ4ܻ͋Ε0͔Β15·ͰͷΛදͤΔͷͰɺ0͔Β9Λͬ ͯेਐͷҰܻΛදݱ͢Δ • ྫ͑ेਐͷ26ɺBCDͰ 0010
0110 ʹͳΔ • BCDجຊใٕज़ऀࢼݧͷࢼݧൣғʹؚ·Ε͍ͯΔ 16
BCDجຊใٕज़ऀࢼݧͷ ࢼݧൣғʹؚ·Ε͍ͯΔ 17
શʹΕͯͨͱ͍͏͔ ֮͑ͨهԱ͢Βͳ͍😇 18
Goݴޠ 19
20
https://go.dev/ref/spec#Constant_expressions υΩϡϝϯτᐌ͘ ఆࣜৗʹਖ਼֬ʹධՁ͞Ε·͢ Constant expressions are always evaluated exactly; 21
22
͓͠·͍ 23
ࢀߟࢿྉ • খΛѻ͏ͳΒBCDΛ࠾༻͍ͯ͠Δݴޠ͕ѹత • https://qiita.com/ma2shita/items/d8aeec9e2921dc3536f4 24