table of contents
std::arg(std::complex)(3) | C++ Standard Libary | std::arg(std::complex)(3) |
NAME¶
std::arg(std::complex) - std::arg(std::complex)
Synopsis¶
Defined in header <complex>
template< class T > (1)
T arg( const complex<T>& z );
long double arg( long double z ); (2) (since C++11)
template< class DoubleOrInteger > (3) (since C++11)
double arg( DoubleOrInteger z );
float arg( float z ); (4) (since C++11)
Calculates the phase angle (in radians) of the complex number z
Additional overloads are provided for float, double, long double, and
all integer types, which are treated as complex numbers with zero (since
C++11)
imaginary component.
Parameters¶
z - complex value
Return value¶
If no errors occur, returns the phase angle of z in the interval [−π; π].
Errors and special cases are handled as if the function is implemented as
std::atan2(std::imag(z), std::real(z)).
Example¶
// Run this code
#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';
}
Output:¶
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
See also¶
abs(std::complex) returns the magnitude of a complex number
(function template)
polar constructs a complex number from magnitude and phase angle
(function template)
atan2
atan2f arc tangent, using signs to determine quadrants
atan2l (function)
(C++11)
(C++11)
atan2(std::valarray) applies the function std::atan2 to a valarray and a
value
(function template)
2022.07.31 | http://cppreference.com |