Math for Pictures
Here's the small subset of math that I use for the vast majority of visualizations - ideally it's a good introduction to those who want to make pretty things with d3js, canvas, or other tools. In essence, I'll try to explain four parts of JavaScript's built-in Math object: Math.cos(a), which we use to get x positions from anglesMath.sin(a), which we use to get y positions from anglesMath.atan2(y,
Why does parseInt(1/0, 19) return 18?
Stack Overflow for Teams is now called Stack Internal. Bring the best of human thought and AI automation together at your work. Try for free Learn more
ã€Javascript】é…列ã®é †åºã®ãƒ©ãƒ³ãƒ€ãƒ 入れ替㈠at softelメモ
å•é¡Œ phpã 㨠shuffle($array)ã§é…列ã®å†…容をランダムãªé †åºã«å…¥ã‚Œæ›¿ãˆã‚‰ã‚Œã‚‹ã˜ã‚ƒãªã„ã§ã™ã‹ã€‚ Javascriptã§ã‚‚é…列ã®è¦ç´ ã®ãƒ©ãƒ³ãƒ€ãƒ 入れ替ãˆã£ã¦ã§ãる？ [0,1,2,3,4,5,6,7,8,9] → [4,6,8,0,9,3,7,1,2] ã®ã‚ˆã†ãªæ„Ÿã˜ã€‚ ç”㈠shuffle()関数ã§é…列ã®è¦ç´ をシャッフルã§ãã‚‹ã®ã¯ã€ä¾¿åˆ©æ©Ÿèƒ½æº€è¼‰ã€é–¢æ•°ã®å¡Šã®phpãªã‚‰ã§ã¯ã®é¢¨æ™¯ã€‚ Javascriptã®Arrayオブジェクトã«shuffleã¯ãªã„。実装方法も考ãˆã¦è‡ªåˆ†ã§ä½œã‚‹å¿…è¦ãŒã‚る。 乱数ã§é‡ã¿ã‚’ã¤ã‘ã¦ä¸¦ã¹æ›¿ãˆã‚‹æ–¹æ³• var x = [0,1,2,3,4,5,6,7,8,9]; //é…列xã®å„è¦ç´ ã«ä¹±æ•°ã§é‡ã¿ã‚’ã¤ã‘ã‚‹ for (var i = 0, l = x.length; i < l; ++i) { x[i] = [x[i], Math.random()]; } //é…列xã‚’
第2回　座標ã®å›žè»¢ã‚’ç†è§£ã™ã‚‹â”€ãƒ–ラウザã§æ“作ã§ãã‚‹JavaScript座標回転プãƒã‚°ãƒ©ãƒ | gihyo.jp
å‰å›žã®å›žè»¢ã™ã‚‹ãƒ—ãƒãƒšãƒ©ã§ã™ãŒã€ã‚½ãƒ¼ã‚¹ã‚’見るã¨sinやらcosやらãŒå‡ºã¦ãã¾ã™ã€‚ã„ã‚ゆる三角関数ã¨ã„ã†ã‚„ã¤ã§ã™ãŒã€å¾—æ„ãªæ–¹ã¯å°‘ãªã„ã‹ã‚‚知れã¾ã›ã‚“（ä¸ã«ã¯è¦‹ã‚‹ã¨ã‚¸ãƒ³ãƒžã‚·ãƒ³ãŒå‡ºã‚‹ã¨ã„ã†æ–¹ã‚‚ã„らã£ã—ゃるã‹ã‚‚知れã¾ã›ã‚“â ）â 。 今回ã¯ã“ã®ã‚ãŸã‚Šã®åº§æ¨™æ“作をã€ç›´è¦³çš„ã«ã‚ã‹ã‚‹ã‚ˆã†ã«è§£èª¬ã—ã¦ã„ãã¾ã—ょã†ã€‚ 座標回転ã®åŸºæœ¬ ã¾ãšã€åº§æ¨™ã«ã¤ã„ã¦å¾©ç¿’ã—ã¦ãŠãã¾ã—ょã†ã€‚普通ã€åº§æ¨™ã¨ã„ã†ã®ã¯ã€Œå³ã«5ã€ä¸Šã«3ã€ã®ã‚ˆã†ãªå½¢ã‚’å–ã‚Šã¾ã™ã€‚「â å³ã«5ã€ã®éƒ¨åˆ†ã‚’x座標ã€ã€Œâ 上ã«3ã€ã®éƒ¨åˆ†ã‚’y座標ã¨å‘¼ã³ã¾ã™ã€‚ ã“ã®åº§æ¨™ã§é•·æ–¹å½¢ã‚’æãã®ã¯ç°¡å˜ã§ã™ã€‚ã§ã¯ãªãœå‰å›žã®ãƒ—ãƒã‚°ãƒ©ãƒ ã§ã¯ã‚„ã‚„ã“ã—ã„ã“ã¨ã‚’ã—ã¦ã„ãŸã®ã§ã—ょã†ã‹ã€‚ãã‚Œã¯ã€ãƒ—ãƒãƒšãƒ©ã®å›žè»¢ã¯ã€x座標ã¨y座標ã ã‘ã§ã¯ã§ããªã„ã‹ã‚‰ã§ã™ã。ã©ã†ã™ã‚Œã°é•·æ–¹å½¢ã‚’回転ã•ã›ãŸåº§æ¨™ã‚’計算ã§ãã‚‹ã§ã—ょã†ã‹ã€‚ ã“ã‚Œã«ã¯ã€Œå³ã«5ã€ä¸Šã«3ã€ã¨ã„ã†ã®ã‚’2ã¤ã«åˆ†ã‘ã¦è€ƒãˆã¾ã™ã€‚ã¾ãšã€Œå³ã«5ã€ã®éƒ¨åˆ†ã¯ï¼ˆ0, 0）ã‹ã‚‰
1
ランã‚ング
ランã‚ング
メンテナンス
リリースã€éšœå®³æƒ…å ±ãªã©ã®ã‚µãƒ¼ãƒ“スã®ãŠçŸ¥ã‚‰ã›
最新ã®äººæ°—エントリーã®é…ä¿¡
j次ã®ãƒ–ックマーク
kå‰ã®ãƒ–ックマーク
lã‚ã¨ã§èªã‚€
eコメント一覧を開ã
oページを開ã
{{#tags}}- {{label}}
{{/tags}}