asin (<valarray>)

Operates on the elements of an input valarray, returning a valarray whose elements are equal to the arcsine of the elements of the input valarray.

template<class Type> 
   valarray<Type> asin( 
      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 arcsine of the elements of the input valarray.

Remarks

The units of the returned elements are in radians.

The return value is a principal value between +pi/2 and –pi/2 that is consistent with the sine value input.

Example

// valarray_asin.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 ] =  0.25 * i - 1;
   valarray<double> va2 ( 9 );

   cout << "The initial valarray is:";
   for (i = 0 ; i < 9 ; i++ )
      cout << " " << va1 [ i ];
   cout << endl;

   va2 = asin ( va1 );
   cout << "The arcsine of the initial valarray is:\n";
   for (i = 0 ; i < 9 ; i++ )
      cout << setw(10) << va2 [ i ]
           << "  radians, which is  "
           << setw(11) << (180/pi) * va2 [ i ]
           << "  degrees" << endl;
}

The initial valarray is: -1 -0.75 -0.5 -0.25 0 0.25 0.5 0.75 1
The arcsine of the initial valarray is:
   -1.5708  radians, which is          -90  degrees
 -0.848062  radians, which is     -48.5904  degrees
 -0.523599  radians, which is          -30  degrees
  -0.25268  radians, which is     -14.4775  degrees
         0  radians, which is            0  degrees
   0.25268  radians, which is      14.4775  degrees
  0.523599  radians, which is           30  degrees
  0.848062  radians, which is      48.5904  degrees
    1.5708  radians, which is           90  degrees

Requirements

Header: <valarray>

Namespace: std