function template
<complex>

std::norm

complex (1)
template<class T> T norm (const complex<T>& x);
complex (1)
template<class T> T norm (const complex<T>& x);
arithmetic type (2)
double norm (ArithmeticType x);  // additional overloads
Norm of complex
Returns the norm value of the complex number x.

The norm value of a complex number is its squared magnitude, defined as the addition of the square of both its real and its imaginary part (without the imaginary unit). This is the square of abs(x).

Only available for instantiations of complex.
Additional overloads are provided for arguments of any fundamental arithmetic type: In this case, the function assumes the value has a zero imaginary component.
The return type is double, except if the argument is float or long double (in which case, the return type is of the same type as the argument).

Parameters

x
Complex value.

Return value

Norm value of x.
T is the type of the components of the complex type (i.e., its value type).

Example

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// norm example
#include <iostream>     // std::cout
#include <complex>      // std::complex, std::norm

int main ()
{
  std::complex<double> mycomplex (3.0,4.0);

  std::cout << "The norm of " << mycomplex << " is " << std::norm(mycomplex) << '\n';

  return 0;
}


Output:

The norm of (3,4) is 25

See also

abs
Absolute value of complex (function template )
pow
Power of complex (function template )