std::atan(std::valarray)
Defined in header <valarray> |
||
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template< class T > valarray<T> atan( const valarray<T>& va ); |
For each element in va
computes arc tangent of the value of the element.
Parameters
va | - | value array to apply the operation to |
Return value
Value array containing arc tangents of the values in va
.
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 ofstd::valarray
are provided. -
std::valarray
,std::slice_array
,std::gslice_array
,std::mask_array
andstd::indirect_array
can be constructed from the replacement type. - All functions accepting an argument of type
const std::valarray&
exceptbegin()
andend()
(since C++11) should also accept the replacement type. - All functions accepting two arguments of type
const std::valarray&
should accept every combination ofconst std::valarray&
and the replacement type. - The return type does not add more than two levels of template nesting over the most deeply-nested argument type.
Possible implementation
template<class T> valarray<T> atan(const valarray<T>& va) { valarray<T> other = va; for (T &i : other) { i = atan(i); } return other; } |
Example
#include <algorithm> #include <cmath> #include <iostream> #include <valarray> auto show = [](char const* title, const std::valarray<float>& va) { std::cout << title << " :"; std::for_each(std::begin(va), std::end(va), [](const float x) { std::cout << " " << std::fixed << x; }); std::cout << '\n'; }; int main() { const std::valarray<float> x = {.1f, .3f, .6f, .9f}; const std::valarray<float> f = std::atan(x); const std::valarray<float> g = std::tan(f); show("x ", x); show("f = atan(x)", f); show("g = tan(f) ", g); }
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
See also
applies the function std::asin to each element of valarray (function template) |
|
applies the function std::acos to each element of valarray (function template) |
|
applies the function std::atan2 to a valarray and a value (function template) |
|
applies the function std::tan to each element of valarray (function template) |
|
(C++11)(C++11)
|
computes arc tangent (\({\small\arctan{x} }\)arctan(x)) (function) |
(C++11)
|
computes arc tangent of a complex number (\({\small\arctan{z} }\)arctan(z)) (function template) |
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