tanh (<valarray>)
Operates on the elements of an input valarray, returning a valarray whose elements are equal to the hyperbolic tangent of the elements of the input valarray.
template<class Type>
valarray<Type> tanh(
const valarray<Type>& _Left
);
Parameters
- _Left
The input valarray whose elements are to be operated on by the member function.
Return Value
A valarray whose elements are equal to the hyperbolic cosine of the elements of the input valarray.
Remarks
Identities defining the hyperbolic tangent in terms of the exponential function:
tanh ( z ) = sinh ( z ) / cosh ( z ) = ( exp ( z ) – exp ( -z ) ) / ( exp ( z ) + exp ( -z ) )
Example
// valarray_tanh.cpp
// compile with: /EHsc
#include <valarray>
#include <iostream>
#include <iomanip>
int main( )
{
using namespace std;
double pi = 3.14159265359;
int i;
valarray<double> va1 ( 9 );
for ( i = 0 ; i < 9 ; i++ )
va1 [ i ] = pi * ( 0.25 * i - 1 );
valarray<double> va2 ( 9 );
cout << "The initial valarray is:\n";
for ( i = 0 ; i < 9 ; i++ )
cout << setw( 10 ) << va1 [ i ]
<< " radians, which is "
<< setw( 5 ) << ( 180/pi ) * va1 [ i ]
<< " degrees" << endl;
cout << endl;
va2 = tanh ( va1 );
cout << "The hyperbolic tangent of the initial valarray is:\n";
for ( i = 0 ; i < 9 ; i++ )
cout << va2 [ i ] << endl;
}
The initial valarray is:
-3.14159 radians, which is -180 degrees
-2.35619 radians, which is -135 degrees
-1.5708 radians, which is -90 degrees
-0.785398 radians, which is -45 degrees
0 radians, which is 0 degrees
0.785398 radians, which is 45 degrees
1.5708 radians, which is 90 degrees
2.35619 radians, which is 135 degrees
3.14159 radians, which is 180 degrees
The hyperbolic tangent of the initial valarray is:
-0.996272
-0.982193
-0.917152
-0.655794
0
0.655794
0.917152
0.982193
0.996272
Requirements
Header: <valarray>
Namespace: std