flucoma-core/tests/algorithms/public/TestKMeans.cpp at d0559274f250e7fa00c49f6a6cf18c7196dde44c · flucoma/flucoma-core · GitHub

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#define CATCH_CONFIG_MAIN
#include <catch2/catch_all.hpp>
#include <flucoma/algorithms/public/KMeans.hpp>

namespace fluid::algorithm {

TEST_CASE("KMeans against hand worked example")
{
  FluidTensor<double, 2>      points{{0, 0}, {0.5, 0.}, {0.5, 1}, {1, 1}};
  FluidTensor<std::string, 1> ids{"0", "1", "2", "3"};

  FluidDataSet<std::string, double, 1> ds(ids, points);

  fluid::algorithm::KMeans algo;
  FluidTensor<double, 2> initialMeans{{0,0},{1,1}};
  algo.setMeans(initialMeans);
  algo.train(ds, 2, 2, KMeans::InitMethod::randomPartion, -1);

  FluidTensor<double, 2> means(2, 2);
  algo.getMeans(means);
  FluidTensor<index, 1> assignments(4);
  algo.getAssignments(assignments);

  auto comp = [](double x, double y) -> bool {
    return Catch::Matchers::WithinRel(x).match(y);
  };

  FluidTensor<double, 2> expected_means{{0.25, 0}, {0.75, 1.0}};

  REQUIRE_THAT(means, Catch::Matchers::RangeEquals(expected_means, comp));
  REQUIRE_THAT(assignments, Catch::Matchers::RangeEquals({0, 0, 1, 1}));
}

TEST_CASE("KMeans is reproducable with manual random seed")
{

  using Tensor = FluidTensor<double, 2>;

  Tensor      points{{0, 0}, {0.5, 0.}, {0.5, 1}, {1, 1}};
  FluidTensor<std::string, 1> ids{"0", "1", "2", "3"};
  FluidDataSet<std::string, double, 1> ds(ids, points);

  std::vector means(3,Tensor(2,2));

  auto initmethod = GENERATE(algorithm::KMeans::InitMethod::randomPartion,
                             algorithm::KMeans::InitMethod::randomPoint,
                             algorithm::KMeans::InitMethod::randomSampling);
  INFO("Init method " << static_cast<long>(initmethod));
  algorithm::KMeans algo;
  algo.train(ds, 2, 1, initmethod,42);
  algo.getMeans(means[0]);
  algo.clear();

  algo.train(ds, 2, 1, initmethod,42);
  algo.getMeans(means[1]);
  algo.clear();

  algo.train(ds, 2, 1, initmethod,4398);
  algo.getMeans(means[2]);
  algo.clear();

  using Catch::Matchers::RangeEquals;
  using Catch::Matchers::WithinRel;
  auto comp = [](double x, double y) -> bool {
    return Catch::Matchers::WithinRel(x).match(y);
  };

  REQUIRE_THAT(means[1], RangeEquals(means[0], comp));
if(static_cast<std::ptrdiff_t>(initmethod) != 2) // can converge for randomsampling
  {
    REQUIRE_THAT(means[1], !RangeEquals(means[2], comp));
  }
}

} // namespace fluid::algorithm