std::atan(std::valarray) - cppreference.com (original) (raw)

| | | | | ---------------------------------------------------------------- | | | | template< class T >valarray<T> atan( const valarray<T>& va ); | | |

For each element in va computes arc tangent of the value of the element.

Contents

• 1 Parameters
• 2 Return value
• 3 Notes
• 4 Possible implementation
• 5 Example
• 6 See also

[edit] Parameters

[edit] Return value

Value array containing arc tangents of the values in va.

[edit] Notes

Unqualified function (atan) is used to perform the computation. If such function is not available, std::atan is used due to argument-dependent lookup.

The function can be implemented with the return type different from std::valarray. In this case, the replacement type has the following properties:

• All const member functions of std::valarray are provided.
• std::valarray, std::slice_array, std::gslice_array, std::mask_array and std::indirect_array can be constructed from the replacement type.
• For every function taking a const std::valarray<T>& except begin() and end()(since C++11), identical functions taking the replacement types shall be added;
• For every function taking two const std::valarray<T>& arguments, identical functions taking every combination of const std::valarray<T>& and replacement types shall be added.
• The return type does not add more than two levels of template nesting over the most deeply-nested argument type.

[edit] Possible implementation

template valarray atan(const valarray& va) { valarray other = va; for (T& i : other) i = atan(i);   return other; // proxy object may be returned }

[edit] Example

Output:

x  : 0.100000 0.300000 0.600000 0.900000 f = atan(x) : 0.099669 0.291457 0.540420 0.732815 g = tan(f)  : 0.100000 0.300000 0.600000 0.900000

[edit] See also