yunfengzhou-hub commented on code in PR #82: URL: https://github.com/apache/flink-ml/pull/82#discussion_r846975117
########## flink-ml-core/src/main/java/org/apache/flink/ml/param/ArrayArrayParam.java: ########## @@ -0,0 +1,42 @@ +/* + * 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.param; + +import org.apache.flink.ml.util.ReadWriteUtils; + +import java.io.IOException; + +/** Class for the arrayOfArray-type parameters. */ +public class ArrayArrayParam<T> extends Param<T[][]> { Review Comment: How about this? ```java DoubleArrayParam SPLITS_ARRAY = new DoubleArrayParam( "splitsArray", "Array of split points.", null, ParamValidators.nonEmptyArray()); default Double[][] getSplitsArray() { Double[] values = get(SPLITS_ARRAY); Double[][] result = new Double[values[0].intValue()][]; int offset = 1; for (int i = 0; i < values[0].intValue(); i++) { result[i] = new Double[values[offset].intValue()]; System.arraycopy(values, offset + 1, result[i], 0, values[offset].intValue()); offset += values[0].intValue() + 1; } return result; } default T setSplitsArray(Double[][] value) { List<Double> list = new ArrayList<>(); list.add((double) value.length); for (Double[] doubles : value) { list.add((double) doubles.length); list.addAll(Arrays.asList(doubles)); } set(SPLITS_ARRAY, list.toArray(new Double[0])); return (T) this; } ``` My point is that we should try to simplify the internal implementation. Currently we have about 6 basic type params, including String, Boolean, Int, Long, Double, Float. For array-typed parameters, we introduced another 6 classes. For 2D-array typed parameters, we would also need 6 classes. Same for 3D, 4D cases. I don't think it would be a good idea to have so many classes for parameters, each of which shares a large proportion in common. For this problem, the solution I proposed in comments above is to reuse 1D classes for arrays of larger dimensions. -- 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]
