log10

Article
03/04/2013

Retourne le logarithme de base 10 d'un nombre complexe.

template<class Type>
   complex<Type> log10(
      const complex<Type>& _ComplexNum
   );

Paramètres

_ComplexNum
Le nombre complexe dont le logarithme de base 10 est déterminé.

Valeur de retour

Le nombre complexe qui est le logarithme de base 10 du nombre complexe d'entrée.

Notes

Les coupes de branche sont le long de le vrai axe négatif.

Exemple

// complex_log10.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 log10 of a complex number c1
   complex <double> c2 = log10 ( c1 );
   cout << "Complex number c2 = log10 ( 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; 

   // log10 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( log10 ( vc1 ) );
   complex <double> vc2  ( polar (1.0, pi / 3) );
   v1.push_back( log10 ( vc2 ) );
   complex <double> vc3  ( polar (1.0, pi / 2) );
   v1.push_back( log10 ( vc3) );
   complex <double> vc4  ( polar (1.0, 2 * pi / 3) );
   v1.push_back( log10 ( vc4 ) );
   complex <double> vc5  ( polar (1.0, 5 * pi / 6) );
   v1.push_back( log10 ( vc5 ) );
   complex <double> vc6  ( polar (1.0,  pi ) );
   v1.push_back( log10 ( vc6 ) );

   cout << "The complex components log10 (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;
}

Résultat de l'exemple

Complex number c1 = (3,4)
Complex number c2 = log10 ( c1 ) = (0.69897,0.402719)
The modulus of c2 is: 0.806686
The argument of c2 is: 0.522706 radians, which is 29.9489 degrees.

The complex components log10 (vci), where abs (vci) = 1
& arg (vci) = i * pi / 6 of the vector v1 are:
(0,0.227396)
(0,0.454792)
(0,0.682188)
(0,0.909584)
(0,1.13698)
(0,-1.36438)

Configuration requise

en-tête : <complex>

l'espace de noms : DST

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