advancedmath.as

支持分数约分/基本三角函数计算的AS3表达式解析类,可以将字符串中的算式解析为结果值.

//Class:AdvancedMath  Author:Swfdong  Date:2007-7-1
package {
	import Fraction;
	public class AdvancedMath {
		private static  var tResult:Fraction;
		private static  var tNumber:Number=0;
		function AdvancedMath() {
		}
		//加法
		public static function plus(num1:Fraction,num2:Fraction):String {
			tResult=new Fraction("1|1");
			tNumber=lcm(num1.denominator,num2.denominator);
			tResult.denominator=tNumber;
			tResult.numerator=fix(num1.numerator*(tNumber/num1.denominator)+num2.numerator*(tNumber/num2.denominator));
			return tResult.value;
		}
		//减法
		public static function minus(num1:Fraction,num2:Fraction):String {
			tResult=new Fraction("1|1");
			tNumber=lcm(num1.denominator,num2.denominator);
			tResult.denominator=tNumber;
			tResult.numerator=fix(num1.numerator*(tNumber/num1.denominator)-num2.numerator*(tNumber/num2.denominator));
			return tResult.value;
		}
		//乘法
		public static function multiply(num1:Fraction,num2:Fraction):String {
			tResult=new Fraction("1|1");
			tResult.denominator=num1.denominator*num2.denominator;
			tResult.numerator=fix(num1.numerator*num2.numerator);
			return tResult.value;
		}
		//除法
		public static function divide(num1:Fraction,num2:Fraction):String {
			tResult=new Fraction("1|1");
			tResult.denominator=num1.denominator*num2.numerator;
			tResult.numerator=fix(num1.numerator*num2.denominator);
			return tResult.value;
		}
		//乘方
		public static function pow(num1:Fraction,num2:Fraction):String {
			tResult=new Fraction("1|1");
			tNumber=num2.numerator/num2.denominator;
			tResult.denominator=Math.pow(num1.denominator,tNumber);
			var tPow:Number=Math.pow(num1.numerator,tNumber);
			tResult.numerator=fix(Math.pow(num1.numerator,tNumber));
			return tResult.value;
		}
		//sin
		public static function sin(num:Fraction):String {
			return Math.sin(num.numerator / num.denominator / 180 * Math.PI);
		}
		//cos
		public static function cos(num:Fraction):String {
			return Math.cos(num.numerator / num.denominator / 180 * Math.PI);
		}
		//tan
		public static function tan(num:Fraction):String {
			return Math.tan(num.numerator / num.denominator / 180 * Math.PI);
		}
		//cot
		public static function cot(num:Fraction):String {
			return 1 / Math.tan(num.numerator / num.denominator / 180 * Math.PI);
		}
		//arcsin
		public static function arcsin(num:Fraction):String {
			return fix(Math.asin(num.numerator / num.denominator * 180 / Math.PI));
		}
		//arccos
		public static function arccos(num:Fraction):String {
			return fix(Math.acos(num.numerator / num.denominator * 180 / Math.PI));
		}
		//arctan
		public static function arctan(num:Fraction):String {
			return fix(Math.atan(num.numerator / num.denominator * 180 / Math.PI));
		}
		//最小公倍数
		public static function lcm(num1:Number,num2:Number):Number {
			var min:Number=Math.min(Math.abs(num1),Math.abs(num2));
			var max:Number=Math.max(Math.abs(num1),Math.abs(num2));
			for (var i:Number = 1; i<Infinity; i++) {
				if ((min*i)%max == 0 ) {
					return min * i * num1 / num2 / Math.abs(num1 / num2);
				}
			}
		}
		//最大公约数
		public static function gcd(num1:Number,num2:Number):Number {
			var min:Number=Math.min(Math.abs(num1),Math.abs(num2));
			var max:Number=Math.max(Math.abs(num1),Math.abs(num2));
			for (var i:Number =min; i>-Infinity; i--) {
				if (min%i == 0 &&max%i==0) {
					return i * num1 / num2 / Math.abs(num1 / num2);
				}
			}
		}
		//保留有效位数
		public static function fix(num:Number):Number {
			var tNum:Number=Math.abs(num%1);
			tNumber=(tNum>0.0000000001)?num:Math.round(num);
			tNumber=(1-tNum>0.0000000001)?tNumber:Math.round(num);
			return tNumber;
		}
	}
}