# std::abs(std::complex) (3) - Linux Manuals

## NAME

std::abs(std::complex) - std::abs(std::complex)

## Synopsis

Defined in header <complex>
template< class T >
T abs( const complex<T>& z );

Returns the magnitude of the complex number z.

## Parameters

z - complex value

## Return value

If no errors occur, returns the absolute value (also known as norm, modulus, or magnitude) of z.
Errors and special cases are handled as if the function is implemented as std::hypot(std::real(z), std::imag(z))

## Examples

// Run this code

#include <iostream>
#include <complex>

int main()
{
std::complex<double> z(1, 1);
std::cout << z << " cartesian is rho = " << std::abs(z)
<< " theta = " << std::arg(z) << " polar\n";
}

## Output:

(1,1) cartesian is rho = 1.41421 theta = 0.785398 polar

returns the phase angle
arg (function template)
constructs a complex number from magnitude and phase angle
polar (function template)

abs(int)
labs
llabs computes absolute value of an integral value (|x|)
(function)

(C++11)

abs(float)
fabs
fabsf
fabsl absolute value of a floating point value (|x|)
(function)

(C++11)
(C++11)

hypot computes square root of the sum of the squares of two given numbers (
hypotf √
hypotl x2
+y2
(C++11) )
(C++11) (function)
(C++11)
applies the function std::abs to each element of valarray
abs(std::valarray) (function template)