Std::asin(std::valarray) (3) Linux Manual Page

std::asin(std::valarray) – std::asin(std::valarray)

Synopsis

Defined in header<valarray>

    template <class T>

    valarray<T> asin(const valarray<T> &va);

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

Parameters

va – value array to apply the operation to

Return value

Value array containing arc sines of the values in va.

Notes

Unqualified function (asin) is used to perform the computation. If such function is not available, std::asin 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> asin(const valarray<T>& va)
  {
      valarray<T> other = va;
      for (T &i : other) {
          i = asin(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 y-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::asin(v1) * 180.0 / pi;
    ;
    for (double n : v2)
        std::cout << std::fixed << n << ' ';
    std::cout << '\n';
}

Output:

-90.000000 -60.000000 -45.000000 -30.000000 0.000000 30.000000 45.000000 60.000000 90.000000

                     applies the function std::acos to each element of valarray
acos(std::valarray) (function template)
                     applies the function std::atan to each element of valarray
atan(std::valarray) (function template)
                     applies the function std::atan2 to a valarray and a value
atan2(std::valarray) (function template)
                     applies the function std::sin to each element of valarray
sin(std::valarray) (function template)
asin
asinf
asinl computes arc sine (arcsin(x))
                     (function)
(C++11)
(C++11)
asin(std::complex) computes arc sine of a complex number (arcsin(z))
                     (function template)
(C++11)

std::asin(std::valarray) (3) Linux Manual Page