cosine_similarity

eve::cosine_similarity = functor<cosine_similarity_t>

inlineconstexpr

Header file

#include <eve/module/core.hpp>

Callable Signatures

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

Parameters

• xs, ys : floating value arguments or tuples of floating value arguments.

Return value

1. cosine_similarity product. \(\frac{\sum_s (x_s*y_s)}{\sqrt{\sum_s (x_s^2)*\sum_s (y_s^2)}}\). It is the cosine of the angle between the two vectors. One or minus one means thaat the vectors are proportionnal, zero that they are orthogonal.
2. Uses the upgraded type for computations and result

See also

`welford_cosine_similarity` for incremental or parallel cosine_similarity and averages computations.

Example

// revision 0
#include <eve/module/core.hpp>
#include <iostream>
#include "../../vec3.hpp"
 
int main()
{
  kumi::tuple wf0{0.0, 1.0, 2.0, 3.0, -1.0, -2.0, -3.0, -4.0};
  kumi::tuple wf1{0.0, -4.0, 1.0, -1.0, 2.0, -2.0, 3.0, -4.0};
 
  std::cout << "<- wf0           = " << wf0 << "\n";
  std::cout << "<- wf1           = " << wf1 << "\n";
 
 
  std::cout << "-> cosine_similarity(wf0, wf1) = " << eve::cosine_similarity(wf0, wf1) << "\n";
  std::cout << "-> cosine_similarity(wf0, wf0) = " << eve::cosine_similarity(wf0, wf0) << "\n";
  vec3<float> a(1.0, 2.0, 3.0);
  vec3<float> b(-3.0, -4.0, -6.0);
  std::cout <<  "a " << a << std::endl;
  std::cout <<  "b " << b << std::endl;
  std::cout << "eve::cosine_similarity(a, b) = "<< eve::cosine_similarity(a, b) << std::endl;
  std::cout << "eve::cosine_similarity(a, a) = " << eve::cosine_similarity(a, a) << std::endl;
  std::cout << "eve::cosine_similarity(b, a) = " << eve::cosine_similarity(b, a) << std::endl;
  std::cout << "eve::cosine_similarity(b, b) = " << eve::cosine_similarity(b, b) << std::endl;
 
  // simd cosine_similarity eve::wide<vec3<float>, eve::fixed<4>>;
  using wv3_t = eve::wide<vec3<float>, eve::fixed<4>>;
  auto wa = wv3_t(a, a, b, b);
  auto wb = wv3_t(b, a, a, b);
   std::cout << "wa " << wa << std::endl;
   std::cout << "wb " << wb << std::endl;
   std::cout << "eve::cosine_similarity[eve::widen](wa, wb) = "<< eve::cosine_similarity(wa, wb) << std::endl;
 
 
  kumi::tuple x{4.0f, 3.0f, 2.0f, 1.0f};
  kumi::tuple y{1.0f, 2.0f, 3.0f, 4.0f};
  std::cout << eve::cosine_similarity(x, x) <<  std::endl;
  std::cout << eve::cosine_similarity(x, y) <<  std::endl;
  std::cout << eve::cosine_similarity(y, x) <<  std::endl;
 
  using w_t = eve::wide<float, eve::fixed<4>>;
  auto wt1 = kumi::generate<11>([](auto p){return w_t([p](auto q){return float(p+q); }); });
  auto wt2 = kumi::generate<11>([](auto p){return w_t([p](auto q){return p*p/float((q+1)); }); });
  std::cout << wt1 << std::endl;
  std::cout << wt2 << std::endl;
 
}