function template
<valarray>
std::atan
template<class T> valarray<T> atan (const valarray<T>& x);
Compute arc tangent of valarray elements
Returns a valarray object containing the principal values of the arc tangent of all the elements of x, expressed in radians, in the same order.
The function calls acos (unqualified) once for each element.
This function overloads cmath's atan.
Parameters
- x
- valarray containing elements of a type for which the unary function atan is defined.
Return value
A valarray object with the arc tangent values of the elements of x.
Example
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// atan valarray example
#include <iostream> // std::cout
#include <cstddef> // std::size_t
#include <cmath> // std::atan(double)
#include <valarray> // std::valarray(valarray)
int main ()
{
double val[] = {0.0, 0.25, 0.5, 0.75, 1.0};
std::valarray<double> foo (val,5);
std::valarray<double> bar = atan (foo);
std::cout << "foo:";
for (std::size_t i=0; i<foo.size(); ++i)
std::cout << ' ' << foo[i];
std::cout << '\n';
std::cout << "bar:";
for (std::size_t i=0; i<bar.size(); ++i)
std::cout << ' ' << bar[i];
std::cout << '\n';
return 0;
}
Output:
foo: 0 0.25 0.5 0.75 1
bar: 0 0.244979 0.463648 0.643501 0.785398
See also
- atan (cmath)
- Compute arc tangent (function)
- atan2
- Compute atan2 of valarray elements (function template)
- tan
- Compute tangent of valarray elements (function template)