std::arg(std::complex)
来自cppreference.com
| 定义于头文件 <complex>
|
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| template< class T > T arg( const complex<T>& z ); |
(1) | |
| long double arg( long double z ); |
(2) | (C++11 起) |
| template< class DoubleOrInteger > double arg( DoubleOrInteger z ); |
(3) | (C++11 起) |
| float arg( float z ); |
(4) | (C++11 起) |
计算复数 z 的辐角（以弧度表示）
(C++11 起)为 float 、 double 、 long double 及所有整数类型提供重载，它们被当做有零虚部的复数
参数
| z | - | 复数值 |
返回值
若无错误发生，则返回 z 在区间 (−π; π) 内的辐角。
错误和特殊情况按照函数宛如以 std::atan2(std::imag(z), std::real(z)) 实现来处理。
示例
运行此代码
#include <iostream> #include <complex> int main() { std::complex<double> z1(1, 0); std::cout << "phase angle of " << z1 << " is " << std::arg(z1) << '\n'; std::complex<double> z2(0, 1); std::cout << "phase angle of " << z2 << " is " << std::arg(z2) << '\n'; std::complex<double> z3(-1, 0); std::cout << "phase angle of " << z3 << " is " << std::arg(z3) << '\n'; std::complex<double> z4(-1, -0.0); std::cout << "phase angle of " << z4 << " (the other side of the cut) is " << std::arg(z4) << '\n'; }
输出：
phase angle of (1,0) is 0 phase angle of (0,1) is 1.5708 phase angle of (-1,0) is 3.14159 phase angle of (-1,-0) (the other side of the cut) is -3.14159
参阅
| 返回复数的模 (函数模板) | |
| 从模和辐角构造复数 (函数模板) | |
| (C++11)(C++11) |
反正切，用符号确定象限 (函数) |
| 应用函数 std::atan2 到一个 valarray 和一个值 (函数模板) |
