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Other References

CSSStyleDeclaration

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JavaScript Math.atan2（）

❮前へ JavaScript数学オブジェクト次へ❯

例-atan2（y、x）

（x、y）座標が（4,8）のポイントがあるとすると、そのポイントと正のX軸の間の角度をラジアンで次のように計算できます。

Math.atan2(8, 4);

定義と使用法

Math.atan2（）メソッドは、引数の商のアークタンジェントをPIと-PIラジアンの間の数値として返します。

返される数値は、正のX軸と点（x、y）の間のラジアン（度ではない）で反時計回りの角度を表します。

注： atan2（）では、y座標が最初の引数として渡され、x座標が2番目の引数として渡されます。

ブラウザのサポート

Math.atan2() ECMAScript1（ES1）機能です。

ES1（JavaScript 1997）は、すべてのブラウザーで完全にサポートされています。


Chrome	IE	Edge	Firefox	Safari	Opera
Yes	Yes	Yes	Yes	Yes	Yes

構文

Math.atan2(y, x)

Parameter	Description
y	Required. A number representing the y coordinate
x	Required. A number representing the x coordinate

戻り値

PIから-PIまでの数値。

値が空の場合はNaN。

関連ページ

JavaScript数学

JavaScript番号

JavaScript番号リファレンス

❮前へ JavaScript数学オブジェクト次へ❯