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.
附加重载为任何 基本算术类型 提供：在这种情况下，函数假定该值为零 虚部。
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).

参数

x
Complex value.

返回值

Norm value of x.
T 是 complex 类型的分量类型（即其值类型）。

示例

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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;
}

输出

The norm of (3,4) is 25


另见

abs
复数的绝对值 (函数模板)
pow
复数的幂 (函数模板)