[C++知识库]C语言在VS2017编译器下实现复数的运算（自编自定义函数）

VS2017编译器关于C语言下，对复数的运算并不支持，利用complex.h头文件并不适用，通过自编的子函数，实现一般性的复数计算，精度与Matlab软件下对比，精度一致。
一、头文件ComplexCalculation.h，用于复数运算的一些函数头和定义

/*ComplexCalculation.h  用于复数运算的一些函数头和定义*/

#ifndef _COMPLEXCALCULATION_H_
	#define _COMPLEXCALCULATION_H_

	#define ASSERT_ENABLE 1

	#define IS_COMPLEX_DIVISOR_CORRENT(DIVISOR_REAL, DIVISOR_IMAG)        ((DIVISOR_REAL != 0) || (DIVISOR_IMAG != 0))
	typedef double                    mathDouble;
	typedef unsigned char             mathUint_8;
	typedef unsigned short int        mathUint_16;
	typedef unsigned int              mathUint_32;

	typedef struct _ReDefcomplex
	{
		mathDouble    Real;
		mathDouble    Imag;
	}complexType;

	complexType    complexAdd(complexType a, complexType b);
	complexType    complexSubtract(complexType minuend, complexType subtrahend);
	complexType    complexMultiply(complexType a, complexType b);
	complexType    complexDivision(complexType dividend, complexType divisor);
	mathDouble     complexAbs(complexType a);
	mathDouble     complexAngle(complexType a);
	complexType    complexByAbsAngle(mathDouble r, mathDouble theta);
	complexType    complexExp(complexType a);

	#if ASSERT_ENABLE
		#define assert_param(expr) ((expr) ? (void)0 : assert_failed((mathUint_8 *)__FILE__, __LINE__))
		void assert_failed(mathUint_8* file, mathUint_32 line);
	#else
		#define assert_param(expr) ((void)0)
	#endif

#endif

二、ComplexCalculation.c，用于复数运算的一些函数

/*ComplexCalculation.c 用于复数运算的一些函数*/

#include "ComplexCalculation.h"
#include "math.h"
#include "stdio.h"

/*函数名：complexAdd
*说明：复数加法
*/
complexType    complexAdd(complexType a, complexType b)
{
	complexType result;
	result.Real = a.Real + b.Real;
	result.Imag = a.Imag + b.Imag;	
	return result;
}
	
/*函数名：complexSubtract
*说明：复数减法
*/
complexType    complexSubtract(complexType minuend, complexType subtrahend)
{
	complexType result;
	result.Real = minuend.Real - subtrahend.Real;
	result.Imag = minuend.Imag - subtrahend.Imag;
	return result;
}

/*函数名：complexMultiply
*说明：复数乘法
*/
complexType complexMultiply(complexType a, complexType b)
{
	complexType result;
	result.Real = a.Real * b.Real - a.Imag * b.Imag;
	result.Imag = a.Imag * b.Real + a.Real * b.Imag;
	return result;
}

/*函数名：complexDivision
*说明：复数除法
*其它：divisor的实部和虚部不能同时为0
*/
complexType complexDivision(complexType dividend, complexType divisor)
{
	complexType result;
	/*断言，被除数的实部和虚部不能同时为零*/
	assert_param(IS_COMPLEX_DIVISOR_CORRENT(divisor.Real, divisor.Imag));
	result.Real = (mathDouble)(dividend.Real * divisor.Real + dividend.Imag * divisor.Imag) / \
	(divisor.Real * divisor.Real + divisor.Imag * divisor.Imag);
	result.Imag = (mathDouble)(dividend.Imag * divisor.Real - dividend.Real * divisor.Imag) / \
	(divisor.Real * divisor.Real + divisor.Imag * divisor.Imag);
	return result;
}

/*函数名：complexAbs
*说明：复数取模（绝对值）
*/
mathDouble    complexAbs(complexType a)
{
	return (sqrt(pow(a.Real, 2) + pow(a.Imag, 2)));
}

/*函数名：complexAngle
*说明：复数取相角
*/
mathDouble    complexAngle(complexType a)
{
/*是atan2而非atan，（-PI,PI] */
	return (atan2(a.Imag, a.Real));
}

/*函数名：complexByAbsAngle
*说明：通过模和相角合成复数
*/
complexType complexByAbsAngle(mathDouble r, mathDouble theta)
{
	complexType tmp_1, tmp_2;
	tmp_1.Real = 0;
	tmp_1.Imag = theta;
	tmp_2 = complexExp(tmp_1);
	tmp_2.Real *= r;
	tmp_2.Imag *= r;
	return tmp_2;
}

/*函数名：complexExp
*说明：复指数运算
*输入：a 复指数
*返回：e的a次方
*其它：使用欧拉公式 e^(jw) = cos(w) + j * sin(w)
*/
complexType complexExp(complexType a)
{
	complexType result;
	result.Real = exp(a.Real) * cos(a.Imag);
	result.Imag = exp(a.Real) * sin(a.Imag);
	return result;
}

#if ASSERT_ENABLE
	/*函数名：assert_failed
	*说明：断言函数
	*输出：打印出错的位置
	*/
	void assert_failed(mathUint_8* file, mathUint_32 line)
	{
		printf("Assert Error in File: %s \r\nLine: %d \r\n", file, line);
	}
#endif

三、主函数通道，main.c

#include "ComplexCalculation.h"
#include "stdio.h"

int main(void)
{
	complexType a, b, c;
	a.Imag = 1.0;
	a.Real = 0;
	b.Real = -0.043369177255479;
	b.Imag = 0.0;

	c = complexAdd(a, b);
	printf("complexAdd: c.Real %20.15lf, c.Imag %20.15lf \r\n", c.Real, c.Imag);

	c = complexSubtract(a, b);
	printf("complexSubtract: c.Real %20.15lf, c.Imag %20.15lf \r\n", c.Real, c.Imag);

	c = complexMultiply(a, b);
	printf("complexMultiply: c.Real %20.15lf, c.Imag %20.15lf \r\n", c.Real, c.Imag);

	c = complexDivision(a, b);
	printf("complexDivision: c.Real %20.15lf, c.Imag %20.15lf \r\n", c.Real, c.Imag);

	printf("Abs(c): %f\r\n", complexAbs(a));
	printf("Angle(c): %f\r\n", complexAngle(a));

	c = complexByAbsAngle(complexAbs(a), complexAngle(a));
	printf("complexByAbsAngle: a.Real %20.15lf, a.Imag %20.15lf \r\n", c.Real, c.Imag);

	c= complexExp(a);
	printf("complexExp: c.Real %20.15lf, c.Imag %20.15lf \r\n", c.Real, c.Imag);
}