xuyang1706 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_r310023003
########## File path: flink-ml-parent/flink-ml-lib/src/main/java/org/apache/flink/ml/common/matrix/DenseMatrix.java ########## @@ -0,0 +1,725 @@ +/* + * 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; + +import java.io.Serializable; +import java.util.Arrays; + +/** + * DenseMatrix stores dense matrix data and provides some methods to operate on + * the matrix it represents. + */ +public class DenseMatrix implements Serializable { + + /** + * Row dimension. + */ + int m; + + /** + * Column dimension. + */ + int n; + + /** + * Array for internal storage of elements. + * <p> + * The matrix data is stored in column major format internally. + */ + double[] data; + + /** + * The default constructor. + */ + DenseMatrix() { + } + + /** + * Construct an m-by-n matrix of zeros. + * + * @param m Number of rows. + * @param n Number of colums. + */ + public DenseMatrix(int m, int n) { + this(m, n, new double[m * n]); + } + + /** + * Construct a matrix from a 1-D array. The data in the array should organize + * in row major. + * + * @param m Number of rows. + * @param n Number of cols. + * @param data One-dimensional array of doubles. + */ + public DenseMatrix(int m, int n, double[] data) { + this(m, n, data, true); + } + + /** + * Construct a matrix from a 1-D array. The data in the array is organized + * in column major or in row major, which is specified by parameter 'inRowMajor' + * + * @param m Number of rows. + * @param n Number of cols. + * @param data One-dimensional array of doubles. + * @param inRowMajor Whether the matrix in 'data' is in row major format. + */ + public DenseMatrix(int m, int n, double[] data, boolean inRowMajor) { + assert (data.length == m * n); + this.m = m; + this.n = n; + if (inRowMajor) { + this.data = new double[m * n]; + for (int i = 0; i < m; i++) { + for (int j = 0; j < n; j++) { + this.set(i, j, data[i * n + j]); + } + } + } else { + this.data = data.clone(); + } + } + + /** + * Construct a matrix from a 2-D array. + * + * @param data Two-dimensional array of doubles. + * @throws IllegalArgumentException All rows must have the same size + */ + public DenseMatrix(double[][] data) { + this.m = data.length; + this.n = data[0].length; + for (int i = 0; i < m; i++) { + if (data[i].length != n) { + throw new IllegalArgumentException("All rows must have the same size."); + } + } + this.data = new double[m * n]; + for (int i = 0; i < m; i++) { + for (int j = 0; j < n; j++) { + this.set(i, j, data[i][j]); + } + } + } + + /** + * Create an identity matrix. + * + * @param n Review comment: Thanks. We added java docs to all methods. ---------------------------------------------------------------- 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
