Question

我想在Flex中编写计算器代码但在网络上找不到任何定点库。

对于计算器，我需要更高的精度，然后IEEE 754可以保证。例如：

trace(1.4 - .4); //should be 1 but it is 0.9999999999999999

有人可以推荐一个好的定点库吗？

提前谢谢

Answer 1

它有效，但并不完美，所有学分都来自http://joshblog.net/2007/01/30/flash-floating-point-number-errors/

的Josh

/**
 * Corrects errors caused by floating point math.
 */
public function correctFloatingPointError(number:Number, precision:int = 5):Number
{
    //default returns (10000 * number) / 10000
    //should correct very small floating point errors
    var correction:Number = Math.pow(10, precision);
    return Math.round(correction * number) / correction;
}
/**
 * Tests if two numbers are <em>almost</em> equal.
 */
public function fuzzyEquals(number1:Number, number2:Number, precision:int = 5):Boolean
{
    var difference:Number = number1 - number2;
    var range:Number = Math.pow(10, -precision);
    //default check:
    //0.00001 <difference> -0.00001
    return difference <range && difference> -range;
}
/*
Copyright (c) 2007 Josh Tynjala
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.
*/

再次感谢你：）

Answer 2

我不知道，但在此期间你可以使用这段代码（不是我的）：

    public static function correctFloatingPointError(number:Number, precision:int = 5):Number
    {
        //default returns (10000 * number) / 10000
        //should correct very small floating point errors

        var correction:Number = Math.pow(10, precision);
        return Math.round(correction * number) / correction;
    }

动作脚本3是否有定点库？

2 个答案: