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Math.absとMath.min Math.maxは何のためにあるの？

```/**
* Copyright tail_y ( http://wonderfl.net/user/tail_y )
*/

// forked from tail_y's forked from: [最適化 Tips] Number, int, uint の計算による処理速度の違い
// forked from muta244's [最適化 Tips] Number, int, uint の計算による処理速度の違い
package {

import flash.display.*;
import flash.geom.*;
import flash.events.*;
import flash.text.*;
import flash.utils.*;

public class Main extends Sprite
{
static private const _NUM_TIMES:int = 1000000;

private function _init():void
{
_debug(
"各テスト " + _NUM_TIMES + " 回処理させた計算結果 [単位 ： ミリ秒]\n" +
"(誤差は多少生じます)\n"
);

_measure("ループのみ", function ():void
{
var n1:Number = Math.random()*10 - 5;
for (var i:uint = 0; i < _NUM_TIMES; i++) {

}
});

_measure("n2 = Math.abs(n1);", function ():void
{
var n1:Number = Math.random()*10 - 5;
var n2:Number;
for (var i:uint = 0; i < _NUM_TIMES; i++) {
n2 = Math.abs(n1);
}
});

_measure("n2 = (0 < n1) ? n1 : -n1;", function ():void
{
var n1:Number = Math.random()*10 - 5;
var n2:Number;
for (var i:uint = 0; i < _NUM_TIMES; i++) {
n2 = (0 < n1) ? n1 : -n1;
}
});

_measure("n3 = Math.max(n1, n2);", function ():void
{
var n1:Number = Math.random()*10 - 5;
var n2:Number = Math.random()*10 - 5;
var n3:Number;
for (var i:uint = 0; i < _NUM_TIMES; i++) {
n3 = Math.max(n1, n2);
}
});

_measure("n3 = (n2 < n1) ? n1 : n2;", function ():void
{
var n1:Number = Math.random()*10 - 5;
var n2:Number = Math.random()*10 - 5;
var n3:Number;
for (var i:uint = 0; i < _NUM_TIMES; i++) {
n3 = (n2 < n1) ? n1 : n2;
}
});

_debug("\n結果については言及しませんので, 各自ご判断ください.");
}

private var _field:TextField;
private var _time:uint;

public function Main():void
{
_setup();
_init();
}

private function _measure(title:String, func:Function, ...params):void
{
_time = getTimer();
func.apply(null, params);
_time = getTimer() - _time;

_debug("[ " + title + " ] --> " + _time + " ms");
}

private function _debug(log:String):void
{
_field.appendText(log + "\n");
}

private function _setup():void
{
_field = new TextField();
_field.width = stage.stageWidth - 40;
_field.height = stage.stageHeight - 60;
_field.x = 20;
_field.y = 60;
_field.multiline = true;
_field.wordWrap = true;

var format:TextFormat = _field.defaultTextFormat;
format.font = "_sans";
_field.defaultTextFormat = format;

var button:Sprite = new Sprite();
button.graphics.lineStyle(1, 0xBBBBBB);
button.graphics.beginFill(0xEEEEEE);
button.graphics.drawRoundRect(0, 0, 100, 20, 5, 5);
button.graphics.endFill();

button.x = 20;
button.y = 20;
button.mouseChildren = false;
button.buttonMode = true;

var field:TextField = new TextField();
field.width = 100;
field.height = 20;
field.htmlText = "<p align='center'><font face='_sans'>再計算</span></p>";