cos_int

eve::cos_int = functor<cos_int_t>

inlineconstexpr

Header file

#include <eve/module/special.hpp>

Callable Signatures

namespace eve
{
   // Regular overload
   constexpr auto cos_int(floating_value auto x)                                   noexcept; // 1
 
   // Lanes masking
   constexpr auto cos_int[conditional_expr auto c](/*any of the above overloads*/) noexcept; // 2
   constexpr auto cos_int[logical_value auto m](/*any of the above overloads*/)    noexcept; // 2
}

Parameters

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

Return value

1. The value of the cosine integral \( \mathbf{Ci}(x) = \displaystyle -\int_x^\infty \frac{\cos t}{t}\;\mbox{d}t\), is returned.
2. The operation is performed conditionnaly.

External references

• Wolfram MathWorld:Cosine Integral
• DLMF: Cosine Integral
• Wikipedia:Cosine integral

Example

// revision 1
#include <eve/module/special.hpp>
#include <iostream>
 
int main()
{
  eve::wide w = {0.0,  -1.0, 1.0, 2.0, 50.0,
                  eve::inf(eve::as<double>()), eve::minf(eve::as<double>()), eve::nan(eve::as<double>())};
 
  std::cout << "<- w                          = " << w << "\n";
 
  std::cout << "-> cos_int(w)                 = " << eve::cos_int(w) << "\n";
  std::cout << "-> cos_int[ignore_last(2)](w) = " << eve::cos_int[eve::ignore_last(2)](w) << "\n";
  std::cout << "-> cos_int[w <= 2.0](w)       = " << eve::cos_int[w <= 2.0](w) << "\n";
}