std::tan(std::valarray)(3)

🌸 std::tan(std::valarray) 🌸

okay bestie, this is a page straight out of the C++ Standard Libary manual, and the star of the show is std::tan(std::valarray) 💅✨ it’s giving trigonometry main character energy, fr fr.

💖 NAME

std::tan(std::valarray) - std::tan(std::valarray)

✨ Synopsis ✨

Defined in header <valarray>:

template< class T >
valarray<T> tan( const valarray<T>& va );

For each element in va, it computes the tangent of that element’s value 🫶

🎀 Parameters 🎀

• va — the value array you’re applying the operation to 🌸

🦋 Return value 🦋

A value array containing the tangents of the values in va ✨

🔥 Notes 🔥

Unqualified function (tan) is used to perform the computation. If such function is not available, std::tan 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.

🧚 Possible implementation 🧚

Here’s one possible implementation — and yes, check that comment, a proxy object may be returned 🙈

template<class T>
valarray<T> tan(const valarray<T>& va)
{
    valarray<T> other = va;
    for (T& i : other)
        i = tan(i);

    return other; // proxy object may be returned
}

🍓 Example 🍓

Run this code, bestie:

#include <cmath>
#include <iostream>
#include <valarray>

auto show = [](char const* title, const std::valarray<double>& va)
{
    std::cout << title << " :";
    for (auto x : va)
        std::cout << "  " << std::fixed << x;
    std::cout << '\n';
};

int main()
{
    const std::valarray<double> x = {.0, .1, .2, .3};
    const std::valarray<double> y = std::tan(x);
    const std::valarray<double> z = std::atan(y);

    show("x          ", x);
    show("y = tan(x) ", y);
    show("z = atan(y)", z);
}

🖨️ Output

x           :  0.000000  0.100000  0.200000  0.300000
y = tan(x)  :  0.000000  0.100335  0.202710  0.309336
z = atan(y) :  0.000000  0.100000  0.200000  0.300000

🌈 See also 🌈

• sin(std::valarray) — applies the function std::sin to each element of valarray (function template)
• cos(std::valarray) — applies the function std::cos to each element of valarray (function template)
• atan(std::valarray) — applies the function std::atan to each element of valarray (function template)
• tan, tanf, tanl — computes tangent (\({\small\tan{x}}\)tan(x)) (function) (C++11) (C++11)
• tan(std::complex) — computes tangent of a complex number (\({\small\tan{z}}\)tan(z)) (function template)

🙈 Hidden category

• Pages with unreviewed LWG DR marker

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signed off by the C++ Standard Libary manual — source/version: http://cppreference.com, date: 2024.06.10, page: std::tan(std::valarray)(3) — byeee bestie, go tangent some arrays 💅✨🫶