exp

auto eve::exp = functor<exp_t>

inlineconstexpr

External references

• C++ standard reference
• Wolfram MathWorld
• DLMF
• Wikipedia
• pmineiro fastapprox
• Schraudolph algorithm

Example

// revision 1
#include <eve/module/math.hpp>
#include <iostream>
 
 
int main()
{
  eve::wide wf = {0.0f, -0.0f, -1.0f, 1.0f, 2.0f,
                  eve::inf(eve::as<float>()), eve::minf(eve::as<float>()), eve::nan(eve::as<float>())};
 
  std::cout << "<- wf                     = " << wf << "\n";
 
  std::cout << "-> exp(wf)                = " << eve::exp(wf) << "\n";
  std::cout << "-> exp[raw](wf)           = " << eve::exp[eve::raw](wf) << "\n";
  std::cout << "-> exp[ignore_last(2)](wf)= " << eve::exp[eve::ignore_last(2)](wf) << "\n";
  std::cout << "-> exp[wf != 2.0f](wf)    = " << eve::exp[wf != 2.0f](wf) << "\n";
 
  std::cout << eve::exp[eve::raw](1.0) << std::endl;
  std::cout << eve::exp[eve::raw](1.0f) << std::endl;
}

Header file

#include <eve/module/math.hpp>

Callable Signatures

namespace eve
{
   // Regular overload
   constexpr auto exp(floating_value auto x)                          noexcept; // 1
 
   // Lanes masking
   constexpr auto exp[conditional_expr auto c](floating_value auto x) noexcept; // 2
   constexpr auto exp[logical_value auto m](floating_value auto x)    noexcept; // 2
   constexpr auto exp[raw](floating_value auto x)                     noexcept; // 3
   constexpr auto exp[fast ](floating_value auto x)                   noexcept; // 3
}

Parameters

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

Return value

1. Returns the elementwise natural exponential of the input. In particular:
   • If the element is \(\pm0\), \(1\) is returned
   • If the element is \(-\infty\), \(+0\) is returned
   • If the element is \(\infty\), \(\infty\) is returned
   • If the element is a NaN, NaN is returned
2. The operation is performed conditionnaly.
3. The raw and fast options use the very fast and quite inacurate Schraudolph's algorithm. and the implementation is largely inspired by pmineiro library. raw generally provides around 5%