---
title: conj
description: "计算复数的共轭。"
url: https://www.hikunpeng.com/document/detail/zh/kunpengboostkithistory/240RC1/accel/kunpengaccel_kml_16_0695.html
sourcePath: /source/zh/kunpengboostkithistory/240RC1/accel/kunpengaccel_kml_16_0695.html
indexId: 172a572e3d9cd55bb351ed017db231153b08ab85f3ab8eb026b2032575b89a4f76
---
# conj

计算复数的共轭。

#### 接口定义

C interface：

float complex conjf(float complex x);

double complex conj(double complex x);

long double complex conjl(long double complex x);


#### 参数

| 参数名 | 类型 | 描述 | 输入/输出 |
| --- | --- | --- | --- |
| x | 在conjf中，x是复数单精度浮点类型。 在conj中，x是复数双精度浮点类型。 在conjl中，x是复数长双精度浮点类型。 | 表示输入数据的浮点值。 | 输入 |


#### 返回值

- 返回x的共轭复数y，y.real ∈ (-INF, +INF)，y.imag∈ (-INF, +INF)。
- 输入x，返回y.real=x.real, y.imag=-x.imag。


#### 依赖

C: "kc.h"


#### 示例

C interface：
```
// typical usage
double x1 = INFINITY, y1 = INFINITY;
double x2 = 2.0, y2 = 3.0;
double x3 = -2.5, y3 = -3.4;
double x4 = NAN, y4 = NAN;
double x5 = 0, y5 = 0;
double complex z1 = conj(__builtin_complex(x1, y1));
double complex z2 = conj(__builtin_complex(x2, y2));
double complex z3 = conj(__builtin_complex(x3, y3));
double complex z4 = conj(__builtin_complex(x4, y4));
double complex z5 = conj(__builtin_complex(x5, y5));
// print result
printf("/*\n");
printf(" * conj(%.2f + %.2f*I) = %.6f + %.6f*I\n", x1, y1, __real__(z1), __imag__(z1));
printf(" * conj(%.2f + %.2f*I) = %.6f + %.6f*I\n", x2, y2, __real__(z2), __imag__(z2));
printf(" * conj(%.2f + %.2f*I) = %.6f + %.6f*I\n", x3, y3, __real__(z3), __imag__(z3));
printf(" * conj(%.2f + %.2f*I) = %.6f + %.6f*I\n", x4, y4, __real__(z4), __imag__(z4));
printf(" * conj(%.2f + %.2f*I) = %.6f + %.6f*I\n", x5, y5, __real__(z5), __imag__(z5));
printf(" **/\n");
/*
* conj(inf + inf*I) = inf + -inf*I
* conj(2.00 + 3.00*I) = 2.000000 + -3.000000*I
* conj(-2.50 + -3.40*I) = -2.500000 + 3.400000*I
* conj(nan + nan*I) = nan + -nan*I
* conj(0.00 + 0.00*I) = 0.000000 + -0.000000*I
**/
```