kronecker

auto kyosu::kronecker = eve::functor<kronecker_t>

inlineconstexpr

tuple_callable computing the \(\delta\) (Kronecker symbol) of its arguments.

@kroneckertogroup functions

Header file

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
   // Regular overloads
   constexpr auto kronecker(auto ... xs)                                              noexcept; // 1
   constexpr auto kronecker(eve::non_empty_product_type auto const& tup)             noexcept; // 2
 
}

! Parameters

 * `xs` :  real or cayley-dickson arguments.
 * `tup` : kumi tuple of arguments.

Return value

1. The value of the kronecker symbol of the arguments as a real value.
2. Same but the arguments are in the tuple.

Example

#include <eve/wide.hpp>
#include <iostream>
#include <kyosu/kyosu.hpp>
 
int main()
{
  using kyosu::kronecker;
  using e_t = float;
  using c_t = kyosu::complex_t<float>;
  using we_t = eve::wide<float, eve::fixed<2>>;
  using wc_t = eve::wide<kyosu::complex_t<float>, eve::fixed<2>>;
 
  std::cout << "Real:        " << "\n";
  e_t e0(3);
  e_t e1(2);
  std::cout << e0 << ", " << e1 << " -> " << kyosu::kronecker(e0, e1) << "\n";
  std::cout << e0 << ", " << e0 << " -> " << kronecker(e0, e0) << "\n";
  std::cout << e0 << ", " << e1 << ", " << e1 << " -> " << kyosu::kronecker(e0, e1, e1) << "\n";
  std::cout << e0 << ", " << e0 << ", " << e0 << " -> " << kronecker(e0, e0, e0) << "\n";
  we_t we0{e0, e1};
  we_t we1(e1);
  std::cout << we0 << ", " << we1 << ", " << we1 << " -> " << kronecker(we0, we1, we1) << "\n";
  std::cout << we0 << ", " << we1 << ", " << we1 << " -> " << kronecker(we0, we1, we1) << "\n";
 
  std::cout << "Complex:     " << "\n";
  c_t c0(1, 5);
  c_t c1(5, 9);
  std::cout << c0 << ", " << c1 << " -> " << kronecker(c0, c1) << "\n";
  std::cout << c0 << ", " << c0 << " -> " << kronecker(c0, c0) << "\n";
  std::cout << c0 << ", " << c1 << ", " << c1 << " -> " << kyosu::kronecker(c0, c1, c1) << "\n";
  std::cout << c0 << ", " << c0 << ", " << c0 << " -> " << kronecker(c0, c0, c0) << "\n";
  wc_t wc0(c0, c1);
  wc_t wc1(c1, c1);
  std::cout << wc0 << ", " << wc1 << " -> " << kronecker(wc0, wc1) << "\n";
 
  return 0;
}