コード例 #1
0
static void AddTreeCtrs(const TTrainData& data,
                        const TSplitTree& currentTree,
                        TFold* fold,
                        TLearnContext* ctx,
                        TStatsFromPrevTree* statsFromPrevTree,
                        TCandidateList* candList) {
    using TSeenProjHash = THashSet<TProjection>;
    TSeenProjHash seenProj;

    // greedy construction
    TProjection binAndOneHotFeaturesTree;
    binAndOneHotFeaturesTree.BinFeatures = currentTree.GetBinFeatures();
    binAndOneHotFeaturesTree.OneHotFeatures = currentTree.GetOneHotFeatures();
    seenProj.insert(binAndOneHotFeaturesTree);

    for (const auto& ctrSplit : currentTree.GetCtrSplits()) {
        seenProj.insert(ctrSplit.Projection);
    }

    TSeenProjHash addedProjHash;
    for (const auto& baseProj : seenProj) {
        if (baseProj.IsEmpty()) {
            continue;
        }
        for (int cf = 0; cf < data.AllFeatures.CatFeatures.ysize(); ++cf) {
            if (data.AllFeatures.CatFeatures[cf].empty() ||
                data.AllFeatures.IsOneHot[cf] ||
                ctx->Rand.GenRandReal1() > ctx->Params.ObliviousTreeOptions->Rsm) {
                continue;
            }

            TProjection proj = baseProj;
            proj.AddCatFeature(cf);

            if (proj.IsRedundant() || proj.GetFullProjectionLength() > ctx->Params.CatFeatureParams->MaxTensorComplexity) {
                continue;
            }

            if (addedProjHash.has(proj)) {
                continue;
            }

            addedProjHash.insert(proj);

            AddCtrsToCandList(*fold, *ctx, proj, candList);
            fold->GetCtrRef(proj);
        }
    }
    THashSet<TSplitCandidate> candidatesToErase;
    for (auto& splitCandidate : statsFromPrevTree->Stats) {
        if (splitCandidate.first.Type == ESplitType::OnlineCtr) {
            if (!addedProjHash.has(splitCandidate.first.Ctr.Projection)) {
                candidatesToErase.insert(splitCandidate.first);
            }
        }
    }
    for (const auto& splitCandidate : candidatesToErase) {
        statsFromPrevTree->Stats.erase(splitCandidate);
    }
}