< cpp‎ | numeric‎ | valarray
Defined in header <valarray>
template< class T >
valarray<T> tan( const valarray<T>& va );

For each element in va computes tangent of the value of the element.


[edit] Parameters

va - value array to apply the operation to

[edit] Return value

Value array containing tangents of the values in va.

[edit] 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:

[edit] Possible implementation

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

[edit] Example

#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);


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

[edit] See also

applies the function std::sin to each element of valarray
(function template) [edit]
applies the function std::cos to each element of valarray
(function template) [edit]
applies the function std::atan to each element of valarray
(function template) [edit]
computes tangent (tan(x))
(function) [edit]
computes tangent of a complex number (tan(z))
(function template) [edit]