tgamma

kyosu::tgamma = eve::functor<tgamma_t>

inlineconstexpr

Computes \(\Gamma(z)\), \(\Gamma(z, x)\) and \(\gamma(z, x)\), the gamma function and the upper and lower incomplete gamma functions.

Header file

#include <kyosu/functions.hpp>

Callable Signatures

namespace kyosu
{
   // regular calls
   constexpr T  tgamma(T z) noexcept;
}

Parameters

• z : Value to process.

Return value

returns \(\Gamma(z)\).

External references

• Wolfram MathWorld: Gamma Function
• Wikipedia: Gamma function

Note

Γ can be used as an alias in code.

Example

#include <kyosu/kyosu.hpp>
#include <eve/wide.hpp>
#include <iostream>
 
int main()
{
 
 using wide_t = eve::wide <double, eve::fixed<4>>;
  wide_t ref1 = { 3.0, 2.0, 1.0, 0.5};
  wide_t imf1 = { 2.0 , -1.0,  -5.0, 0.0};
  wide_t ref2 = { 0.0, 1.0, 2.0, 3.0};
  auto zc = kyosu::complex_t<wide_t>(ref1, imf1);
 
  std::cout
    << "---- simd" << std::endl
    << "<- zc                          = " << zc << std::endl
    << "-> tgamma(zc)                  = " << kyosu::tgamma(zc)<< std::endl
    << "-> tgamma(ref2)                = " << kyosu::tgamma(ref2) << std::endl
    << "-> Γ(ref2)                 = " << kyosu::Γ(ref2) << std::endl;
}