zhipeng93 commented on code in PR #150: URL: https://github.com/apache/flink-ml/pull/150#discussion_r961445127
########## flink-ml-lib/src/main/java/org/apache/flink/ml/feature/idf/IDFModel.java: ########## @@ -0,0 +1,156 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.flink.ml.feature.idf; + +import org.apache.flink.api.common.functions.RichMapFunction; +import org.apache.flink.api.java.typeutils.RowTypeInfo; +import org.apache.flink.ml.api.Model; +import org.apache.flink.ml.common.broadcast.BroadcastUtils; +import org.apache.flink.ml.common.datastream.TableUtils; +import org.apache.flink.ml.linalg.BLAS; +import org.apache.flink.ml.linalg.DenseVector; +import org.apache.flink.ml.linalg.Vector; +import org.apache.flink.ml.param.Param; +import org.apache.flink.ml.util.ParamUtils; +import org.apache.flink.ml.util.ReadWriteUtils; +import org.apache.flink.streaming.api.datastream.DataStream; +import org.apache.flink.table.api.Table; +import org.apache.flink.table.api.bridge.java.StreamTableEnvironment; +import org.apache.flink.table.api.internal.TableImpl; +import org.apache.flink.table.catalog.ResolvedSchema; +import org.apache.flink.types.Row; +import org.apache.flink.util.Preconditions; + +import org.apache.commons.lang3.ArrayUtils; + +import java.io.IOException; +import java.util.Collections; +import java.util.HashMap; +import java.util.Map; +import java.util.Objects; + +/** A Model which transforms data using the model data computed by {@link IDF}. */ +public class IDFModel implements Model<IDFModel>, IDFModelParams<IDFModel> { + private final Map<Param<?>, Object> paramMap = new HashMap<>(); + private Table modelDataTable; + + public IDFModel() { + ParamUtils.initializeMapWithDefaultValues(paramMap, this); + } + + @Override + @SuppressWarnings("unchecked") + public Table[] transform(Table... inputs) { + Preconditions.checkArgument(inputs.length == 1); + StreamTableEnvironment tEnv = + (StreamTableEnvironment) ((TableImpl) inputs[0]).getTableEnvironment(); + + DataStream<Row> data = tEnv.toDataStream(inputs[0]); + DataStream<IDFModelData> idfModelData = IDFModelData.getModelDataStream(modelDataTable); + + final String broadcastModelKey = "broadcastModelKey"; + ResolvedSchema schema = inputs[0].getResolvedSchema(); + RowTypeInfo inputTypeInfo = TableUtils.getRowTypeInfo(schema); + RowTypeInfo outputTypeInfo = + new RowTypeInfo( + ArrayUtils.addAll( + inputTypeInfo.getFieldTypes(), + TableUtils.getTypeInfoByName(schema, getInputCol())), + ArrayUtils.addAll(inputTypeInfo.getFieldNames(), getOutputCol())); + + DataStream<Row> output = + BroadcastUtils.withBroadcastStream( + Collections.singletonList(data), + Collections.singletonMap(broadcastModelKey, idfModelData), + inputList -> { + DataStream input = inputList.get(0); + return input.map( + new ComputeTfIdfFunction(broadcastModelKey, getInputCol()), + outputTypeInfo); + }); + + return new Table[] {tEnv.fromDataStream(output)}; + } + + @Override + public IDFModel setModelData(Table... inputs) { + modelDataTable = inputs[0]; + return this; + } + + @Override + public Table[] getModelData() { + return new Table[] {modelDataTable}; + } + + @Override + public Map<Param<?>, Object> getParamMap() { + return paramMap; + } + + @Override + public void save(String path) throws IOException { + ReadWriteUtils.saveMetadata(this, path); + ReadWriteUtils.saveModelData( + IDFModelData.getModelDataStream(modelDataTable), + path, + new IDFModelData.ModelDataEncoder()); + } + + /** + * Loads model data from path. + * + * @param tEnv Stream table environment. + * @param path Model path. + * @return IDFModel model. + */ + public static IDFModel load(StreamTableEnvironment tEnv, String path) throws IOException { + IDFModel model = ReadWriteUtils.loadStageParam(path); + + Table modelDataTable = + ReadWriteUtils.loadModelData(tEnv, path, new IDFModelData.ModelDataDecoder()); + return model.setModelData(modelDataTable); + } + + /** Computes the tf-idf for each term in the input document. */ Review Comment: `tf-idf` is a normal feature engineering method. I have added a wiki link[1] in the java doc: [1] https://en.wikipedia.org/wiki/Tf%E2%80%93idf -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
