atan


function template
<valarray> 
template<class T> valarray<T> atan (const valarray<T>& x);

Compute arc tangent of valarray elements

Returns a valarray object containing the principal value of the arc tangent of all the elements of x, expressed in radians.

This function overloads cmath's atan function.

Parameters

x
valarray containing elements of a type for which the unary function atan is defined.


Return value

A valarray object with the arc tangent values of the elements of x.

Example

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// atan valarray example
#include <iostream>
#include <cmath>
#include <valarray>
using namespace std;

int main ()
{
  double val[] = {0.0, 0.25, 0.5, 0.75, 1.0};
  valarray<double> foo (val,5);

  valarray<double> bar = atan (foo);

  cout << "foo: ";
  for (size_t i=0; i<foo.size(); ++i)
	  cout << foo[i] << ' ';
  cout << endl;

  cout << "bar: ";
  for (size_t i=0; i<bar.size(); ++i)
	  cout << bar[i] << ' ';
  cout << endl;

  return 0;
}


Output:

foo: 0 0.25 0.5 0.75 1
bar: 0 0.244979 0.463648 0.643501 0.785398


See also

atan (cmath) Compute arc tangent (function)
atan2 Compute atan2 of valarray elements (function template)
tan Compute tangent of valarray elements (function template)