walterddr commented on a change in pull request #8631: [FLINK-12745][ml] add sparse and dense vector class, and dense matrix class with basic operations. URL: https://github.com/apache/flink/pull/8631#discussion_r309813136
########## File path: flink-ml-parent/flink-ml-lib/src/main/java/org/apache/flink/ml/common/matrix/DenseMatrixUtil.java ########## @@ -0,0 +1,72 @@ +/* + * 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.matrix; + +/** + * DenseMatrixUtil provides some operations over DenseMatrix. + */ +public class DenseMatrixUtil { + + /** + * Provides access to DenseMatrix's internal data buffer. Be aware that + * the data is stored in column major. + * + * @param mat The matrix. + * @return The matrix's internal data buffer. + */ + public static double[] getDataBuffer(DenseMatrix mat) { + return mat.data; Review comment: wonder whether we should allow this. it does not return a copy of the internal array. If I create another DenseMatrix using `createFromBuffer` it seems like it is easy for users to accidentally touch the other one. I think at lease one of these should be a deep copy. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
