text: /*!
  
  @authors Andrei Novikov (pyclustering@yandex.ru)
  @date 2014-2020
  @copyright BSD-3-Clause
  
  */
  
  
  #include <gtest/gtest.h>
  
  #include <algorithm>
  
  #include <pyclustering/utils/linalg.hpp>
  
  
  using namespace pyclustering::utils::linalg;
  
  
  TEST(utest_lingalg, subtract) {
      std::vector<double> a = { 2, 3, 4, 5 };
      std::vector<double> b = { 1, 2, 3, 4 };
  
      auto result = subtract(a, b);
  
      std::vector<double> expected = { 1, 1, 1, 1 };
      ASSERT_EQ(expected, result);
  }
  
  TEST(utest_lingalg, subtract_with_number) {
      std::vector<double> a = { 2, 4, 6, 8 };
  
      auto result = subtract(a, 2);
  
      std::vector<double> expected = { 0, 2, 4, 6 };
      ASSERT_EQ(expected, result);
  }
  
  TEST(utest_lingalg, multiply) {
      std::vector<double> a = { 2, 3, 4, 5 };
      std::vector<double> b = { 1, 2, 3, 4 };
  
      auto result = multiply(a, b);
  
      std::vector<double> expected = { 2, 6, 12, 20 };
      ASSERT_EQ(expected, result);
  }
  
  TEST(utest_lingalg, multiply_with_number) {
      std::vector<double> a = { 2, 3, 4, 5 };
  
      auto result = multiply(a, 2);
  
      std::vector<double> expected = { 4, 6, 8, 10 };
      ASSERT_EQ(expected, result);
  }
  
  TEST(utest_lingalg, multiply_matrix) {
      matrix a = { { 1, 1 }, { 2, 2 }, { 3, 3 } };
      std::vector<double> b = { 2, 2 };
  
      auto result = multiply(a, b);
  
      matrix expected = { { 2, 2 }, { 4, 4 }, { 6, 6 } };
      ASSERT_EQ(expected, result);
  }
  
  TEST(utest_lingalg, divide) {
      std::vector<double> a = { 2, 6, 9, 16 };
      std::vector<double> b = { 2, 2, 3, 4 };
  
      auto result = divide(a, b);
  
      std::vector<double> expected = { 1, 3, 3, 4 };
      ASSERT_EQ(expected, result);
  }
  
  TEST(utest_lingalg, divide_with_number) {
      std::vector<double> a = { 10, 20, 30, 40 };
  
      auto result = divide(a, 5);
  
      std::vector<double> expected = { 2, 4, 6, 8 };
      ASSERT_EQ(expected, result);
  }
  
  TEST(utest_linalg, sum_vector) {
      std::vector<double> a = { 1, 2, 3 };
      ASSERT_EQ(6, sum(a));
  }
  
  TEST(utest_linalg, sum_matrix) {
      matrix a = { { 1, 1 }, { 2, 2 }, { 3, 3 } };
      std::vector<double> expected = { 6, 6 };
      ASSERT_EQ(expected, sum(a, 0));
  
      expected = { 2, 4, 6 };
      ASSERT_EQ(expected, sum(a, 1));
  }