complex number

/**
 * Copyright enecre ( http://wonderfl.net/user/enecre )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/rOeJ
 */

//大学のJava演習をasで。
//Javaの int hoge = 0; みたいな書き方が嫌いです。何となく。
//乗算だけが課題なのでそれしか定義してません（◞‸◟）
package {
    import flash.display.Sprite;
    import flash.text.TextField;
    public class FlashTest extends Sprite {
        public function FlashTest() {
            // write as3 code here..
            var rot30:Complex = new Complex(Math.sqrt(0.75),0.5);
            var tf:TextField = new TextField();
            tf.width = 500;
            tf.text = rot30.toString();
            var rot90:Complex = Complex.multiple(Complex.multiple(rot30,rot30),rot30);
            tf.appendText("\n");
            tf.appendText(rot90.toString());
            addChild(tf);
        }
    }
}
class Complex{
	private var _Re:Number;
	private var _Im:Number;
	public function Complex(_x:Number,_y:Number):void{
		this._Re = _x;
		this._Im = _y;
	}
	public static function multiple(a:Complex,b:Complex):Complex{
		var len:Number = a.length() * b.length();
		var rot:Number = a.rot() + b.rot();
		var ret:Complex = new Complex(len*Math.cos(rot),len*Math.sin(rot));
		return ret;
	}
	private function n2(n:Number):Number{
		return Math.round(n*100)/100;
	}
	public function toString():String{
		return String(n2(this._Re)) + " + " + String(n2(this._Im)) + "i";
	}
	public function length():Number{
		return Math.sqrt(this._Re*this._Re+this._Im*this._Im);
	}
	public function rot():Number{
		return Math.atan2(this._Im,this._Re);
	}
}