Function TEST

tests/cpp/common/test_stats.cc:18–43

namespace xgboost::common {
TEST(Stats, Quantile) {
  Context ctx;
  {
    linalg::Tensor<float, 1> arr({20.f, 0.f, 15.f, 50.f, 40.f, 0.f, 35.f}, {7}, DeviceOrd::CPU());
    std::vector<size_t> index{0, 2, 3, 4, 6};
    auto h_arr = arr.HostView();
    auto beg = MakeIndexTransformIter([&](size_t i) { return h_arr(index[i]); });
    auto end = beg + index.size();
    auto q = Quantile(&ctx, 0.40f, beg, end);
    ASSERT_EQ(q, 26.0);

    q = Quantile(&ctx, 0.20f, beg, end);
    ASSERT_EQ(q, 16.0);

    q = Quantile(&ctx, 0.10f, beg, end);
    ASSERT_EQ(q, 15.0);
  }

  {
    std::vector<float> vec{1., 2., 3., 4., 5.};
    auto beg = MakeIndexTransformIter([&](size_t i) { return vec[i]; });
    auto end = beg + vec.size();
    auto q = Quantile(&ctx, 0.5f, beg, end);
    ASSERT_EQ(q, 3.);
  }
}

TEST(Stats, WeightedQuantile) {
  Context ctx;