Function MakeDataProvider

catboost/libs/train_interface/catboost_api.cpp:21–79

using namespace NCB;

static TDataProviderPtr MakeDataProvider(
    TConstArrayRef<float> features,
    ui32 fCount,
    TConstArrayRef<float> labels,
    TConstArrayRef<float> weights,
    TConstArrayRef<float> baseline
    ) {

    TDataProviderBuilderOptions builderOptions;

    THolder<IDataProviderBuilder> dataProviderBuilder;
    IRawFeaturesOrderDataVisitor* builderVisitor;

    CreateDataProviderBuilderAndVisitor(builderOptions,
                                        &NPar::LocalExecutor(),
                                        &dataProviderBuilder,
                                        &builderVisitor);

    TDataMetaInfo metaInfo;
    metaInfo.TargetType = ERawTargetType::Float;
    metaInfo.TargetCount = 1;
    metaInfo.HasWeights = weights.data() != nullptr;
    if (baseline.data() != nullptr) {
        metaInfo.BaselineCount = baseline.size() / labels.size();
    }
    metaInfo.FeaturesLayout = new TFeaturesLayout((ui32) fCount);

    const size_t samplesCount = features.size() / fCount;

    builderVisitor->Start(metaInfo,
                          samplesCount,
                          EObjectsOrder::Ordered, {});

    for (ui32 f = 0; f < fCount; ++f) {
        auto valHolder =
            MakeIntrusive<TTypeCastArrayHolder<float, float>>(
                TMaybeOwningConstArrayHolder<float>::CreateNonOwning(
                    features.Slice(f * samplesCount, samplesCount)));
        builderVisitor->AddFloatFeature(f, valHolder);
    }


    builderVisitor->AddTarget(
        MakeIntrusive<TTypeCastArrayHolder<float, float>>(
            TMaybeOwningConstArrayHolder<float>::CreateNonOwning(labels)));
    if (weights.data() != nullptr) {
        builderVisitor->AddWeights(weights);
    }

    if (baseline.data() != nullptr) {
        const ui32 baselineCount = baseline.size() / labels.size();
        for (ui32 baselineIdx = 0; baselineIdx < baselineCount; ++baselineIdx) {
            builderVisitor->AddBaseline(baselineIdx, baseline.Slice(baselineIdx * labels.size(), labels.size()));
        }
    }
    builderVisitor->Finish();

    return dataProviderBuilder->GetResult();