log
Restituisce il logaritmo naturale di un numero complesso.
template<class Type>
complex<Type> log(
const complex<Type>& _ComplexNum
);
Parametri
- _ComplexNum
Il numero complesso di cui il logaritmo naturale ancora specificato.
Valore restituito
Il numero complesso che rappresenta il logaritmo naturale del numero complesso di input.
Note
Taglio dei branch sono lungo l'asse reale negativo.
Esempio
// complex_log.cpp
// compile with: /EHsc
#include <vector>
#include <complex>
#include <iostream>
int main() {
using namespace std;
double pi = 3.14159265359;
complex <double> c1 ( 3.0 , 4.0 );
cout << "Complex number c1 = " << c1 << endl;
// Values of log of a complex number c1
complex <double> c2 = log ( c1 );
cout << "Complex number c2 = log ( c1 ) = " << c2 << endl;
double absc2 = abs ( c2 );
double argc2 = arg ( c2 );
cout << "The modulus of c2 is: " << absc2 << endl;
cout << "The argument of c2 is: "<< argc2 << " radians, which is "
<< argc2 * 180 / pi << " degrees." << endl << endl;
// log of the standard angles
// in the first two quadrants of the complex plane
vector <complex <double> > v1;
vector <complex <double> >::iterator Iter1;
complex <double> vc1 ( polar (1.0, pi / 6) );
v1.push_back( log ( vc1 ) );
complex <double> vc2 ( polar (1.0, pi / 3) );
v1.push_back( log ( vc2 ) );
complex <double> vc3 ( polar (1.0, pi / 2) );
v1.push_back( log ( vc3) );
complex <double> vc4 ( polar (1.0, 2 * pi / 3) );
v1.push_back( log ( vc4 ) );
complex <double> vc5 ( polar (1.0, 5 * pi / 6) );
v1.push_back( log ( vc5 ) );
complex <double> vc6 ( polar (1.0, pi ) );
v1.push_back( log ( vc6 ) );
cout << "The complex components log (vci), where abs (vci) = 1 "
<< "\n& arg (vci) = i * pi / 6 of the vector v1 are:\n" ;
for ( Iter1 = v1.begin() ; Iter1 != v1.end() ; Iter1++ )
cout << *Iter1 << " " << endl;
}
Esempio di output
Complex number c1 = (3,4)
Complex number c2 = log ( c1 ) = (1.60944,0.927295)
The modulus of c2 is: 1.85746
The argument of c2 is: 0.522706 radians, which is 29.9489 degrees.
The complex components log (vci), where abs (vci) = 1
& arg (vci) = i * pi / 6 of the vector v1 are:
(0,0.523599)
(0,1.0472)
(0,1.5708)
(0,2.0944)
(0,2.61799)
(0,-3.14159)
Requisiti
complesso <diIntestazione: >
Spazio dei nomi: std