dot

eve::dot = functor<dot_t>

inlineconstexpr

Warning

This is not a reduction ! For reals the dot product is the product

Header file

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
   // Regular overloads
   constexpr auto dot(auto value... xs, auto value... ys)        noexcept; // 1
   constexpr auto dot(kumi::tuple xs, kumi::tuple ys)            noexcept; // 2
 
   // Semantic options
   constexpr auto dot[widen](/*any of the above overloads*/)     noexcept; // 3
}

Parameters

• xs, ys : floating value arguments or tuples of them.
• c: Conditional expression masking the operation.
• m: Logical value masking the operation.

Return value

1. dot product. \(\sum_s x_s*y_s\).
2. use the content of the tuples
3. The summation is computed in the double sized element type (if available). This decorator has no effect on double and 64 bits integrals.

Example

// revision 0
#include <eve/module/core.hpp>
#include <iostream>
 
int main()
{
  eve::wide wf0{0.0, 1.0, 2.0, 3.0, -1.0, -2.0, -3.0, -4.0};
  eve::wide wf1{0.0, -4.0, 1.0, -1.0, 2.0, -2.0, 3.0, -3.0};
  eve::wide wi0{0, 1, 2, 3, -1, -2, -3, -4};
  eve::wide wi1{0, -4, 1, -1, 2, -2, 3, -3};
  eve::wide wu0{0u, 1u, 2u, 3u, 4u, 5u, 6u, 7u};
  eve::wide wu1{7u, 6u, 5u, 4u, 3u, 2u, 1u, 0u};
 
  std::cout << "<- wf0           = " << wf0 << "\n";
  std::cout << "<- wf1           = " << wf1 << "\n";
  std::cout << "<- wi0           = " << wi0 << "\n";
  std::cout << "<- wi1           = " << wi1 << "\n";
  std::cout << "<- wu0           = " << wu0 << "\n";
  std::cout << "<- wu1           = " << wu1 << "\n";
 
  std::cout << "-> dot(wf0, wf1) = " << eve::dot(wf0, wf1) << "\n";
  std::cout << "-> dot(wu0, wu1) = " << eve::dot(wu0, wu1) << "\n";
  std::cout << "-> dot(wi0, wi1)  = " << eve::dot(wi0, wi1) << "\n";
  std::cout << "-> dot(wf0, wf1, wf0, wf1) = "<< eve::dot(wf0, wf1, wf0, wf1) << "\n";
  std::cout << "-> dot[kahan](wf0, wf1, wf0, wf1) = "<< eve::dot[eve::kahan](wf0, wf1, wf0, wf1) << "\n";
  std::cout << "-> dot[widen](wf0, wf1, wf0, wf1) = "<< eve::dot[eve::widen](wf0, wf1, wf0, wf1) << "\n";
 
   auto vwf0= kumi::tuple{wf0, 2*wf0, 3*wf0};
   auto vwf1= kumi::tuple{wf1, 2*wf1, 3*wf1};
   std::cout << "-> dot(vwf0, vwf1)        = " << eve::dot(vwf0, vwf1) << "\n";
   std::cout << "-> dot[widen](vwf0, vwf1) = " << eve::dot[eve::widen](vwf0, vwf1) << "\n";
   std::cout << "-> dot[kahan](vwf0, vwf1) = " << eve::dot[eve::kahan](vwf0, vwf1) << "\n";
}