cacosh函数用法详解

cacosh函数简介

• 头文件包含

#include <complex.h>

• 函数定义

double complex cacosh(double complex  z );
float complex cacoshf(float complex  z );
long double complex cacoshl(long double complex  z );

• 编译链接选项

-lm

cacosh函数常见使用错误

• 链接错误
  undefined reference to `cacosh'
  解决办法：添加链接选项

-lm

• 编译错误
  warning: implicit declaration of function ‘cacosh’ [-Wimplicit-function-declaration]
  解决办法：包含头文件

#include <complex.h>

cacosh函数详细描述

这些函数计算z 的复圆弧双曲余弦，如果y = cacosh(z)，然后z = ccosh(y)。在区间[\-pi，pi]中选择y的虚部。选择y的实部为非负。
一个有：

   cacosh(z) = 2 * clog(csqrt((z + 1) / 2) + csqrt((z \- 1) / 2))

cacosh函数使用举例

/* Link with "\-lm" */

#include <complex.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>

int
main(int argc, char *argv[])
{
   double complex z, c, f;

   if (argc != 3) {
       fprintf(stderr, "Usage: %s <real> <imag>\en", argv[0]);
       exit(EXIT_FAILURE);
   }

   z = atof(argv[1]) + atof(argv[2]) * I;

   c = cacosh(z);
   printf("cacosh() = %6.3f %6.3f*i\en", creal(c), cimag(c));

   f = 2 * clog(csqrt((z + 1)/2) + csqrt((z \- 1)/2));
   printf("formula  = %6.3f %6.3f*i\en", creal(f2), cimag(f2));

   exit(EXIT_SUCCESS);
}