Exemple #1
0
    /**
     * Train a Deep Learning neural net model
     *
     * @param model Input model (e.g., from initModel(), or from a previous training run)
     * @return Trained model
     */
    public final DeepLearningModel trainModel(DeepLearningModel model) {
      Frame validScoreFrame = null;
      Frame train, trainScoreFrame;
      try {
        //      if (checkpoint == null && !quiet_mode) logStart(); //if checkpoint is given, some
        // Job's params might be uninitialized (but the restarted model's parameters are correct)
        if (model == null) {
          model = DKV.get(dest()).get();
        }
        Log.info(
            "Model category: "
                + (_parms._autoencoder
                    ? "Auto-Encoder"
                    : isClassifier() ? "Classification" : "Regression"));
        final long model_size = model.model_info().size();
        Log.info(
            "Number of model parameters (weights/biases): " + String.format("%,d", model_size));
        model.write_lock(_job);
        _job.update(0, "Setting up training data...");
        final DeepLearningParameters mp = model.model_info().get_params();

        // temporary frames of the same "name" as the orig _train/_valid (asking the parameter's
        // Key, not the actual frame)
        // Note: don't put into DKV or they would overwrite the _train/_valid frames!
        Frame tra_fr = new Frame(mp._train, _train.names(), _train.vecs());
        Frame val_fr = _valid != null ? new Frame(mp._valid, _valid.names(), _valid.vecs()) : null;

        train = tra_fr;
        if (model._output.isClassifier() && mp._balance_classes) {
          _job.update(0, "Balancing class distribution of training data...");
          float[] trainSamplingFactors =
              new float
                  [train
                      .lastVec()
                      .domain()
                      .length]; // leave initialized to 0 -> will be filled up below
          if (mp._class_sampling_factors != null) {
            if (mp._class_sampling_factors.length != train.lastVec().domain().length)
              throw new IllegalArgumentException(
                  "class_sampling_factors must have "
                      + train.lastVec().domain().length
                      + " elements");
            trainSamplingFactors =
                mp._class_sampling_factors.clone(); // clone: don't modify the original
          }
          train =
              sampleFrameStratified(
                  train,
                  train.lastVec(),
                  train.vec(model._output.weightsName()),
                  trainSamplingFactors,
                  (long) (mp._max_after_balance_size * train.numRows()),
                  mp._seed,
                  true,
                  false);
          Vec l = train.lastVec();
          Vec w = train.vec(model._output.weightsName());
          MRUtils.ClassDist cd = new MRUtils.ClassDist(l);
          model._output._modelClassDist =
              _weights != null ? cd.doAll(l, w).rel_dist() : cd.doAll(l).rel_dist();
        }
        model.training_rows = train.numRows();
        if (_weights != null && _weights.min() == 0 && _weights.max() == 1 && _weights.isInt()) {
          model.training_rows = Math.round(train.numRows() * _weights.mean());
          Log.warn(
              "Not counting "
                  + (train.numRows() - model.training_rows)
                  + " rows with weight=0 towards an epoch.");
        }
        Log.info("One epoch corresponds to " + model.training_rows + " training data rows.");
        trainScoreFrame =
            sampleFrame(
                train,
                mp._score_training_samples,
                mp._seed); // training scoring dataset is always sampled uniformly from the training
                           // dataset
        if (trainScoreFrame != train) Scope.track(trainScoreFrame);

        if (!_parms._quiet_mode)
          Log.info("Number of chunks of the training data: " + train.anyVec().nChunks());
        if (val_fr != null) {
          model.validation_rows = val_fr.numRows();
          // validation scoring dataset can be sampled in multiple ways from the given validation
          // dataset
          if (model._output.isClassifier()
              && mp._balance_classes
              && mp._score_validation_sampling
                  == DeepLearningParameters.ClassSamplingMethod.Stratified) {
            _job.update(0, "Sampling validation data (stratified)...");
            validScoreFrame =
                sampleFrameStratified(
                    val_fr,
                    val_fr.lastVec(),
                    val_fr.vec(model._output.weightsName()),
                    null,
                    mp._score_validation_samples > 0
                        ? mp._score_validation_samples
                        : val_fr.numRows(),
                    mp._seed + 1,
                    false /* no oversampling */,
                    false);
          } else {
            _job.update(0, "Sampling validation data...");
            validScoreFrame = sampleFrame(val_fr, mp._score_validation_samples, mp._seed + 1);
            if (validScoreFrame != val_fr) Scope.track(validScoreFrame);
          }
          if (!_parms._quiet_mode)
            Log.info(
                "Number of chunks of the validation data: " + validScoreFrame.anyVec().nChunks());
        }

        // Set train_samples_per_iteration size (cannot be done earlier since this depends on
        // whether stratified sampling is done)
        model.actual_train_samples_per_iteration =
            computeTrainSamplesPerIteration(mp, model.training_rows, model);
        // Determine whether shuffling is enforced
        if (mp._replicate_training_data
            && (model.actual_train_samples_per_iteration
                == model.training_rows * (mp._single_node_mode ? 1 : H2O.CLOUD.size()))
            && !mp._shuffle_training_data
            && H2O.CLOUD.size() > 1
            && !mp._reproducible) {
          if (!mp._quiet_mode)
            Log.info(
                "Enabling training data shuffling, because all nodes train on the full dataset (replicated training data).");
          mp._shuffle_training_data = true;
        }
        if (!mp._shuffle_training_data
            && model.actual_train_samples_per_iteration == model.training_rows
            && train.anyVec().nChunks() == 1) {
          if (!mp._quiet_mode)
            Log.info(
                "Enabling training data shuffling to avoid training rows in the same order over and over (no Hogwild since there's only 1 chunk).");
          mp._shuffle_training_data = true;
        }

        //        if (!mp._quiet_mode) Log.info("Initial model:\n" + model.model_info());
        long now = System.currentTimeMillis();
        model._timeLastIterationEnter = now;
        if (_parms._autoencoder) {
          _job.update(0, "Scoring null model of autoencoder...");
          if (!mp._quiet_mode) Log.info("Scoring the null model of the autoencoder.");
          model.doScoring(
              trainScoreFrame,
              validScoreFrame,
              _job._key,
              0,
              false); // get the null model reconstruction error
        }
        // put the initial version of the model into DKV
        model.update(_job);
        model.total_setup_time_ms += now - _job.start_time();
        Log.info("Total setup time: " + PrettyPrint.msecs(model.total_setup_time_ms, true));
        Log.info("Starting to train the Deep Learning model.");
        _job.update(0, "Training...");

        // main loop
        for (; ; ) {
          model.iterations++;
          model.set_model_info(
              mp._epochs == 0
                  ? model.model_info()
                  : H2O.CLOUD.size() > 1 && mp._replicate_training_data
                      ? (mp._single_node_mode
                          ? new DeepLearningTask2(
                                  _job._key,
                                  train,
                                  model.model_info(),
                                  rowFraction(train, mp, model),
                                  model.iterations)
                              .doAll(Key.make(H2O.SELF))
                              .model_info()
                          : // replicated data + single node mode
                          new DeepLearningTask2(
                                  _job._key,
                                  train,
                                  model.model_info(),
                                  rowFraction(train, mp, model),
                                  model.iterations)
                              .doAllNodes()
                              .model_info())
                      : // replicated data + multi-node mode
                      new DeepLearningTask(
                              _job._key,
                              model.model_info(),
                              rowFraction(train, mp, model),
                              model.iterations)
                          .doAll(train)
                          .model_info()); // distributed data (always in multi-node mode)
          if (stop_requested() && !timeout()) break; // cancellation
          if (!model.doScoring(
              trainScoreFrame, validScoreFrame, _job._key, model.iterations, false))
            break; // finished training (or early stopping or convergence)
          if (timeout()) break; // stop after scoring
        }

        // replace the model with the best model so far (if it's better)
        if (!stop_requested()
            && _parms._overwrite_with_best_model
            && model.actual_best_model_key != null
            && _parms._nfolds == 0) {
          DeepLearningModel best_model = DKV.getGet(model.actual_best_model_key);
          if (best_model != null
              && best_model.loss() < model.loss()
              && Arrays.equals(best_model.model_info().units, model.model_info().units)) {
            if (!_parms._quiet_mode)
              Log.info("Setting the model to be the best model so far (based on scoring history).");
            DeepLearningModelInfo mi = best_model.model_info().deep_clone();
            // Don't cheat - count full amount of training samples, since that's the amount of
            // training it took to train (without finding anything better)
            mi.set_processed_global(model.model_info().get_processed_global());
            mi.set_processed_local(model.model_info().get_processed_local());
            model.set_model_info(mi);
            model.update(_job);
            model.doScoring(trainScoreFrame, validScoreFrame, _job._key, model.iterations, true);
            assert (best_model.loss() == model.loss());
          }
        }
        // store coefficient names for future use
        // possibly change
        model.model_info().data_info().coefNames();
        if (!_parms._quiet_mode) {
          Log.info(
              "==============================================================================================================================================================================");
          if (stop_requested()) {
            Log.info("Deep Learning model training was interrupted.");
          } else {
            Log.info("Finished training the Deep Learning model.");
            Log.info(model);
          }
          Log.info(
              "==============================================================================================================================================================================");
        }
      } finally {
        if (model != null) {
          model.deleteElasticAverageModels();
          model.unlock(_job);
          if (model.actual_best_model_key != null) {
            assert (model.actual_best_model_key != model._key);
            DKV.remove(model.actual_best_model_key);
          }
        }
      }
      return model;
    }
Exemple #2
0
    @Override
    protected void compute2() {
      _model = null; // Resulting model!
      try {
        Scope.enter(); // Cleanup temp keys
        init(true); // Do any expensive tests & conversions now
        // Do lock even before checking the errors, since this block is finalized by unlock
        // (not the best solution, but the code is more readable)
        _parms.read_lock_frames(SharedTree.this); // Fetch & read-lock input frames
        if (error_count() > 0)
          throw H2OModelBuilderIllegalArgumentException.makeFromBuilder(SharedTree.this);

        // New Model?  Or continuing from a checkpoint?
        if (_parms._checkpoint && DKV.get(_parms._model_id) != null) {
          _model = DKV.get(_dest).get();
          _model.write_lock(_key); // do not delete previous model; we are extending it
        } else { // New Model
          // Compute the zero-tree error - guessing only the class distribution.
          // MSE is stddev squared when guessing for regression.
          // For classification, guess the largest class.
          _model =
              makeModel(
                  _dest,
                  _parms,
                  initial_MSE(_response, _response),
                  _valid == null
                      ? Double.NaN
                      : initial_MSE(_response, _vresponse)); // Make a fresh model
          _model.delete_and_lock(_key); // and clear & write-lock it (smashing any prior)
          _model._output._init_f = _initialPrediction;
        }

        // Compute the response domain; makes for nicer printouts
        String[] domain = _response.domain();
        assert (_nclass > 1 && domain != null) || (_nclass == 1 && domain == null);
        if (_nclass == 1) domain = new String[] {"r"}; // For regression, give a name to class 0

        // Compute class distribution, used to for initial guesses and to
        // upsample minority classes (if asked for).
        if (_nclass > 1) { // Classification?

          // Handle imbalanced classes by stratified over/under-sampling.
          // initWorkFrame sets the modeled class distribution, and
          // model.score() corrects the probabilities back using the
          // distribution ratios
          if (_model._output.isClassifier() && _parms._balance_classes) {

            float[] trainSamplingFactors =
                new float
                    [_train
                        .lastVec()
                        .domain()
                        .length]; // leave initialized to 0 -> will be filled up below
            if (_parms._class_sampling_factors != null) {
              if (_parms._class_sampling_factors.length != _train.lastVec().domain().length)
                throw new IllegalArgumentException(
                    "class_sampling_factors must have "
                        + _train.lastVec().domain().length
                        + " elements");
              trainSamplingFactors =
                  _parms._class_sampling_factors.clone(); // clone: don't modify the original
            }
            Frame stratified =
                water.util.MRUtils.sampleFrameStratified(
                    _train,
                    _train.lastVec(),
                    _train.vec(_model._output.weightsName()),
                    trainSamplingFactors,
                    (long) (_parms._max_after_balance_size * _train.numRows()),
                    _parms._seed,
                    true,
                    false);
            if (stratified != _train) {
              _train = stratified;
              _response = stratified.vec(_parms._response_column);
              _weights = stratified.vec(_parms._weights_column);
              // Recompute distribution since the input frame was modified
              MRUtils.ClassDist cdmt2 =
                  _weights != null
                      ? new MRUtils.ClassDist(_nclass).doAll(_response, _weights)
                      : new MRUtils.ClassDist(_nclass).doAll(_response);
              _model._output._distribution = cdmt2.dist();
              _model._output._modelClassDist = cdmt2.rel_dist();
            }
          }
          Log.info("Prior class distribution: " + Arrays.toString(_model._output._priorClassDist));
          Log.info("Model class distribution: " + Arrays.toString(_model._output._modelClassDist));
        }

        // Also add to the basic working Frame these sets:
        //   nclass Vecs of current forest results (sum across all trees)
        //   nclass Vecs of working/temp data
        //   nclass Vecs of NIDs, allowing 1 tree per class

        // Current forest values: results of summing the prior M trees
        for (int i = 0; i < _nclass; i++) _train.add("Tree_" + domain[i], _response.makeZero());

        // Initial work columns.  Set-before-use in the algos.
        for (int i = 0; i < _nclass; i++) _train.add("Work_" + domain[i], _response.makeZero());

        // One Tree per class, each tree needs a NIDs.  For empty classes use a -1
        // NID signifying an empty regression tree.
        for (int i = 0; i < _nclass; i++)
          _train.add(
              "NIDs_" + domain[i],
              _response.makeCon(
                  _model._output._distribution == null
                      ? 0
                      : (_model._output._distribution[i] == 0 ? -1 : 0)));

        // Tag out rows missing the response column
        new ExcludeNAResponse().doAll(_train);

        // Variable importance: squared-error-improvement-per-variable-per-split
        _improvPerVar = new float[_ncols];

        // Sub-class tree-model-builder specific build code
        buildModel();
        done(); // Job done!
      } catch (Throwable t) {
        Job thisJob = DKV.getGet(_key);
        if (thisJob._state == JobState.CANCELLED) {
          Log.info("Job cancelled by user.");
        } else {
          t.printStackTrace();
          failed(t);
          throw t;
        }
      } finally {
        if (_model != null) _model.unlock(_key);
        _parms.read_unlock_frames(SharedTree.this);
        if (_model == null) Scope.exit();
        else {
          Scope.exit(
              _model._key,
              ModelMetrics.buildKey(_model, _parms.train()),
              ModelMetrics.buildKey(_model, _parms.valid()));
        }
      }
      tryComplete();
    }