sqrt

計算複雜數值的平方根。

template<class Type>
   complex<Type> sqrt(
      const complex<Type>& _ComplexNum
   );

參數

• _ComplexNum
  要尋找的平方根的複數。

傳回值

複雜數值的平方根。

備註

這個平方根都會有半開放間隔的一個相位角 (- pi/2 之間， pi/2]。

在這個複雜型別的分支切割是與負數虛擬的座標軸。

複雜數值平方根的將會是輸入數字和引數的平方根是二的位數可以不該輸入數字的模組數目。

範例

// complex_sqrt.cpp
// compile with: /EHsc
#include <complex>
#include <iostream>

int main( )
{
   using namespace std;
   double pi = 3.14159265359;

   // Complex numbers can be entered in polar form with
   // modulus and argument parameter inputs but are
   // stored in Cartesian form as real & imag coordinates
   complex <double> c1 ( polar ( 25.0 , pi / 2 ) );
   complex <double> c2 = sqrt ( c1 );
   cout << "c1 = polar ( 5.0 ) = " << c1 << endl;
   cout << "c2 = sqrt ( c1 ) = " << c2 << endl;


   // The modulus and argument of a complex number can be recovered
   double absc2 = abs ( c2 );
   double argc2 = arg ( c2 );
   cout << "The modulus of c2 is recovered from c2 using: abs ( c2 ) = "
        << absc2 << endl;
   cout << "Argument of c2 is recovered from c2 using:\n arg ( c2 ) = "
        << argc2 << " radians, which is " << argc2 * 180 / pi
        << " degrees." << endl;
   
   // The modulus and argument of c2 can be directly calculated
   absc2 = sqrt( abs ( c1 ) );
   argc2 = 0.5 * arg ( c1 );
   cout << "The modulus of c2 = sqrt( abs ( c1 ) ) =" << absc2 << endl;
   cout << "The argument of c2 = ( 1 / 2 ) * arg ( c1 ) ="
        << argc2 << " radians,\n which is " << argc2 * 180 / pi
        << " degrees." << endl;
}

需求

標題: <complex>

命名空間: std