std::exp(std::valarray) - cppreference.com (original) (raw)
| | | | | --------------------------------------------------------------- | | | | template< class T >valarray<T> exp( const valarray<T>& va ); | | |
For each element in va computes e raised to the power equal to the value of the element.
Contents
[edit] Parameters
| va | - | value array to apply the operation to |
|---|
[edit] Return value
Value array containing e raised by the values in va.
[edit] Notes
Unqualified function (exp) is used to perform the computation. If such function is not available, std::exp 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 exp(const valarray& va) { valarray other = va; for (T& i : other) i = exp(i); return other; // proxy object may be returned }
[edit] Example
This example demonstrates the Euler's identity eiπ = -1 and the related exponents.
Output:
(+1.000000,+0.000000) (+0.000000,+1.000000) (-1.000000,+0.000000) (-0.000000,-1.000000) (+1.000000,-0.000000)