Fanoid commented on code in PR #210: URL: https://github.com/apache/flink-ml/pull/210#discussion_r1113947913
########## flink-ml-lib/src/main/java/org/apache/flink/ml/common/gbt/GBTModelParams.java: ########## @@ -0,0 +1,56 @@ +/* + * 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.common.gbt; + +import org.apache.flink.ml.classification.gbtclassifier.GBTClassifierModel; +import org.apache.flink.ml.common.param.HasCategoricalCols; +import org.apache.flink.ml.common.param.HasFeaturesCol; +import org.apache.flink.ml.common.param.HasLabelCol; +import org.apache.flink.ml.common.param.HasPredictionCol; +import org.apache.flink.ml.param.Param; +import org.apache.flink.ml.param.StringArrayParam; +import org.apache.flink.ml.regression.gbtregressor.GBTRegressorModel; + +/** + * Params of {@link GBTClassifierModel} and {@link GBTRegressorModel}. + * + * <p>If the input features come from 1 column of vector type, `featuresCol` should be used, and all + * features are treated as continuous features. Otherwise, `inputCols` should be used for multiple + * columns. Columns whose names specified in `categoricalCols` are treated as categorical features, + * while others are continuous features. + * + * <p>NOTE: `inputCols` and `featuresCol` are in conflict with each other, so they should not be set + * at the same time. In addition, `inputCols` has a higher precedence than `featuresCol`, that is, + * `featuresCol` is ignored when `inputCols` is not `null`. + * + * @param <T> The class type of this instance. + */ +public interface GBTModelParams<T> + extends HasFeaturesCol<T>, HasLabelCol<T>, HasCategoricalCols<T>, HasPredictionCol<T> { + + Param<String[]> INPUT_COLS = new StringArrayParam("inputCols", "Input column names.", null); Review Comment: I'm OK to rename `HasInputCols` to `HasFeaturesCols`. The reason to have both two parameters is related with the handling of categorical columns. SparkML's implementation only supports a vector column as input, but it can store meta information in its schema [1], so the algorithm can distinguish between numerical and categorical values. In Flink, there is no way to store meta information for one vector column. So when end-users want to feed categorical values, our implementation can only accept the data as multiple columns through `HasFeaturesCols`. Otherwise, `HasFeaturesCol` is used. [1] https://github.com/apache/spark/blob/27ed89b7be5ebb91e4a0b106b1669a7867a6012d/mllib/src/main/scala/org/apache/spark/ml/classification/GBTClassifier.scala#L194 -- 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: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
