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pow (<valarray>)

Operates on the elements of input valarrays and constants, returning a valarray whose elements are equal to a base specified either by the elements of an input valarray or a constant raised to an exponent specified either by the elements of an input valarray or a constant.

template<class Type>
   valarray<Type> pow(
      const valarray<Type>& _Left,
      const valarray<Type>& _Right
   );
template<class Type>
   valarray<Type> pow(
      const valarray<Type>& _Left, 
      const Type& _Right
   );
template<class Type>
   valarray<Type> pow(
      const Type& _Left, 
      const valarray<Type>& _Right
   );

_Left

The input valarray whose elements supply the base for each element to be exponentiated.

_Right

The input valarray whose elements supply the power for each element to be exponentiated.

A valarray whose elements I are equal to:

  • _Left [ I ] raised to the power _Right [ I ] for the first template function.

  • _Left [ I ] raised to the power _Right for the second template function.

  • _Left raised to the power _Right [ I ] for the third template function.

If _Left and _Right have a different number of elements, the result is undefined.

#include <valarray>
#include <iostream>
#include <iomanip>

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

   valarray<double> vabase ( 6 );
   for ( i = 0 ; i < 6 ; i++ )
      vabase [ i ] =  i/2;
   valarray<double> vaexp ( 6 );
   for ( i = 0 ; i < 6 ; i++ )
      vaexp [ i ] =  2 * i;

   valarray<double> va2 ( 6 );

   cout << "The initial valarray for the base is: ( ";
      for ( i = 0 ; i < 6 ; i++ )
         cout << vabase [ i ] << " ";
   cout << ")." << endl;

   cout << "The initial valarray for the exponent is: ( ";
      for ( i = 0 ; i < 6 ; i++ )
         cout << vaexp[ i ] << " ";
   cout << ")." << endl;

   va2 = pow ( vabase , vaexp );
   cout << "The power of (n/2) * exp (2n) for n = 0 to n = 5 is: \n";
      for ( i = 0 ; i < 6 ; i++ )
         cout <<  "n = " << i << "\tgives " << va2 [ i ] << endl;
}
The initial valarray for the base is: ( 0 0 1 1 2 2 ).
The initial valarray for the exponent is: ( 0 2 4 6 8 10 ).
The power of (n/2) * exp (2n) for n = 0 to n = 5 is:
n = 0   gives 1
n = 1   gives 0
n = 2   gives 1
n = 3   gives 1
n = 4   gives 256
n = 5   gives 1024

Header: <valarray>

Namespace: std

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