std::acos(std::valarray)
From cppreference.com
Defined in header <valarray>
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template< class T > valarray<T> acos( const valarray<T>& va ); |
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For each element in va
computes arc cosine of the value of the element.
Parameters
va | - | value array to apply the operation to |
Return value
Value array containing arc cosines of the values in va
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Notes
Unqualified function (acos) is used to perform the computation. If such function is not available, std::acos 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.
- All functions accepting an argument of type const std::valarray& except begin() and end() (since C++11) should also accept the replacement type.
- All functions accepting two arguments of type const std::valarray& should accept every combination of const 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> acos(const valarray<T>& va) { valarray<T> other = va; for (T &i : other) { i = acos(i); } return other; } |
Example
Run this code
#include <cmath> #include <iostream> #include <valarray> const double pi = 4.0 * atan(1.0); int main() { // take common x-values from unit circle std::valarray<double> v1 = {-1.0, -sqrt(3.0)/2.0, -sqrt(2.0)/2.0, -0.5, 0.0, 0.5, sqrt(2.0)/2.0, sqrt(3.0)/2.0, 1.0}; std::valarray<double> v2 = std::acos(v1) * 180.0 / pi;; for(double n : v2) std::cout << std::fixed << n << ' '; std::cout << '\n'; }
Output:
180.000000 150.000000 135.000000 120.000000 90.000000 60.000000 45.000000 30.000000 0.000000
See also
applies the function std::asin to each element of valarray (function template) | |
applies the function std::atan to each element of valarray (function template) | |
applies the function std::atan2 to a valarray and a value (function template) | |
applies the function std::cos to each element of valarray (function template) | |
(C++11)(C++11) |
computes arc cosine (arccos(x)) (function) |
(C++11) |
computes arc cosine of a complex number (arccos(z)) (function template) |