• <ins id="pjuwb"></ins>
    <blockquote id="pjuwb"><pre id="pjuwb"></pre></blockquote>
    <noscript id="pjuwb"></noscript>
          <sup id="pjuwb"><pre id="pjuwb"></pre></sup>
            <dd id="pjuwb"></dd>
            <abbr id="pjuwb"></abbr>

            S.l.e!ep.¢%

            像打了激速一樣,以四倍的速度運轉,開心的工作
            簡單、開放、平等的公司文化;尊重個性、自由與個人價值;
            posts - 1098, comments - 335, trackbacks - 0, articles - 1
              C++博客 :: 首頁 :: 新隨筆 :: 聯(lián)系 :: 聚合  :: 管理

            How to compare double or float in Cpp

            Posted on 2010-03-06 16:13 S.l.e!ep.¢% 閱讀(713) 評論(0)  編輯 收藏 引用 所屬分類: VC

            簡單方便型:

            double i=90.02;
            if (? (i-90.02) >= 0.00?)

            How to compare double or float in Cpp

            From MetaSharp

            Jump to: navigation, search

            Article Author(s): Audric Thevenet
            All Rights Reserved.


            language?: english definition of the double type

            The following code is the best way I could come up with to work correctly with doubles. The float version is not provided yet, but after reading a bit the code, you should manage to easily extend it to floats. The most important functions here are:

            • GetExpoBase2() extracts the base2 exponent from the double (putting aside the sign bit and the mantissa)
            • Equals() gets the exponents (e1,e2) of both doubles (d1,d2) and the exponent (e3) of their difference (d1-d2), then the 2 doubles (d1,d2) are considered being equal only if their difference is close enough to 0. This is done comparing the exponents. Example: e3=-50 (meaning 2^-50) e1=-1 e2=-1 then e3-e2=-49 and e3-e1=-49 both less than -48. It means that e1 and e2 are equal because their difference significant bits are located 2^48 lower... hard to tell if it's clear enough, I'll edit later if I come up with a clearer explaination ^^

            Download Double comparison Sample for VC2005

            compare.cpp

            // compare.cpp
            #include "compare.h"
            
            namespace metasharp
            {
            	inline int GetExpoBase2(double d)
            	{
            		int i = 0;
            		((short *)(&i))[0] = (((short *)(&d))[3] & (short)32752); // _123456789ab____ & 0111111111110000
            		return (i >> 4) - 1023;
            	}
            
            	bool	Equals(double d1, double d2)
            	{
            		if (d1 == d2)
            			return true;
            		int e1 = GetExpoBase2(d1);
            		int e2 = GetExpoBase2(d2);
            		int e3 = GetExpoBase2(d1 - d2);
            		if ((e3 - e2 < -48) && (e3 - e1 < -48))
            			return true;
            		return false;
            	}
            
            	int 	Compare(double d1, double d2)
            	{
            		if (Equals(d1, d2) == true)
            			return 0;
            		if (d1 > d2)
            			return 1;
            		return -1;
            	}
            
            	bool	Greater(double d1, double d2)
            	{
            		if (Equals(d1, d2) == true)
            			return false;
            		if (d1 > d2)
            			return true;
            		return false;
            	}
            
            	bool	GreaterOrEqual(double d1, double d2)
            	{
            		if (Equals(d1, d2) == true)
            			return true;
            		if (d1 > d2)
            			return true;
            		return false;
            	}
            
            	bool	Less(double d1, double d2)
            	{
            		if (Equals(d1, d2) == true)
            			return false;
            		if (d1 < d2)
            			return true;
            		return false;
            	}
            
            	bool	LessOrEqual(double d1, double d2)
            	{
            		if (Equals(d1, d2) == true)
            			return true;
            		if (d1 < d2)
            			return true;
            		return false;
            	}
            }
            

            compare.h

            // compare.h
            #ifndef COMPARE_H
            #define COMPARE_H
            
            namespace metasharp
            {
            	int 	Compare(double d1, double d2);
            	bool	Equals(double d1, double d2);
            	bool	Greater(double d1, double d2);
            	bool	GreaterOrEqual(double d1, double d2);
            	bool	Less(double d1, double d2);
            	bool	LessOrEqual(double d1, double d2);
            }
            
            #endif
            
            Retrieved from "
            99精品久久久久久久婷婷| 久久噜噜久久久精品66| 亚洲AV无码1区2区久久 | 欧美久久久久久精选9999| 大美女久久久久久j久久| 思思久久99热免费精品6| 嫩草伊人久久精品少妇AV| 久久精品国产精品亚洲精品| 久久精品无码一区二区日韩AV| 久久午夜福利无码1000合集| 久久棈精品久久久久久噜噜| 久久国产成人| 国产精品久久久久久| 久久九九久精品国产| 久久人爽人人爽人人片AV| 久久精品国产一区二区| 99久久精品费精品国产一区二区 | 久久精品国产亚洲综合色| 看全色黄大色大片免费久久久| 久久久噜噜噜久久熟女AA片| 伊人久久大香线蕉综合5g| 成人国内精品久久久久影院VR| 综合久久国产九一剧情麻豆| 热久久国产欧美一区二区精品| 国产国产成人精品久久| 狼狼综合久久久久综合网| 国产精品中文久久久久久久| 久久亚洲国产成人精品无码区| 欧美一区二区精品久久| 无码国产69精品久久久久网站| 亚洲人成网站999久久久综合| 久久久青草青青亚洲国产免观| 国产精品美女久久久久久2018| 久久WWW免费人成—看片| 91精品国产综合久久精品| 人妻无码中文久久久久专区| 2019久久久高清456| 久久精品国产AV一区二区三区 | 国产精品久久久久久久久鸭| 日韩人妻无码精品久久免费一 | 国产精品伊人久久伊人电影|