atanpi

auto eve::atanpi = functor<atanpi_t>

inlineconstexpr

Header file

#include <eve/module/math.hpp>

Callable Signatures

namespace eve
{
   // Regular overload
   constexpr auto atanpi(floating_value auto x)                          noexcept; // 1
 
   // Lanes masking
   constexpr auto atanpi[conditional_expr auto c](floating_value auto x) noexcept; // 2
   constexpr auto atanpi[logical_value auto m](floating_value auto x)    noexcept; // 2
}

Parameters

• x: floating value.
• c: Conditional expression masking the operation.
• m: Logical value masking the operation.

Return value

1. Returns the elementwise value in \(\pi\) multiples of the arc tangent of the input in the range \(]-\frac12, \frac12]\). In particular:
   • If the element is \(\pm0\), \(\pm0\) is returned.
   • If the element is \(\pm\infty\), \(\pm\frac12\) is returned.
   • If the element is a Nan, NaN is returned.
2. The operation is performed conditionnaly.

External references

• C++ standard reference: atan
• Wolfram MathWorld: Inverse Tangent
• Wikipedia: Inverse trigonometric functions
• DLMF: Inverse trigonometric functions

Example

// revision 1
#include <eve/module/math.hpp>
#include <iostream>
 
int main()
{
  eve::wide wf = { 0.0f, 0.99f, -1.0f, -0.5f, -5.0f, 6.25f, 1.0f, -2.0f};
 
  std::cout << "<- wf                        = " << wf << "\n";
 
  std::cout << "-> atanpi(wf)                = " << eve::atanpi(wf) << "\n";
  std::cout << "-> atanpi[ignore_last(2)](wf)= " << eve::atanpi[eve::ignore_last(2)](wf) << "\n";
  std::cout << "-> atanpi[wf != -2.0f](wf)   = " << eve::atanpi[wf != -2.0f](wf) << "\n";
}