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std::asin(std::valarray)

From cppreference.com
< cpp‎ | numeric‎ | valarray
 
 
 
 
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.

Contents

[edit] Parameters

va - value array to apply the operation to

[edit] Return value

Value array containing arc sines of the values in va.

[edit] 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:

[edit] 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; // proxy object may be returned
}

[edit] Example

#include <cmath>
#include <iostream>
#include <numbers>
#include <valarray>
 
int main()
{
    // take common y-values from unit circle
    const double s22 = std::sqrt(2.0) / 2.0;
    const double s32 = std::sqrt(3.0) / 2.0;
    const std::valarray<double> v1 =
        {-1.0, -s32, -s22, -0.5,  0.0,  0.5, s22,  s32,  1.0};
 
    // fill with results of radians to degrees conversion
    const std::valarray<double> v2 = 
        std::asin(v1) * 180.0 / std::numbers::pi;
 
    for (std::cout << std::showpos; double n : v2)
        std::cout << n << "° ";
    std::cout << '\n';
}

Output:

-90° -60° -45° -30° +0° +30° +45° +60° +90°

[edit] See also

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