yunfengzhou-hub commented on a change in pull request #37: URL: https://github.com/apache/flink-ml/pull/37#discussion_r765560374
########## File path: flink-ml-core/src/main/java/org/apache/flink/ml/linalg/SparseVector.java ########## @@ -0,0 +1,177 @@ +/* + * 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.linalg; + +import org.apache.flink.api.common.typeinfo.TypeInfo; +import org.apache.flink.ml.linalg.typeinfo.SparseVectorTypeInfoFactory; +import org.apache.flink.util.Preconditions; + +import java.util.Arrays; +import java.util.Objects; + +/** A sparse vector of double values. */ +@TypeInfo(SparseVectorTypeInfoFactory.class) +public class SparseVector implements Vector { + public final int n; + public final int[] indices; + public final double[] values; + + public SparseVector(int n, int[] indices, double[] values) { + this.n = n; + this.indices = indices; + this.values = values; + checkSizeAndIndicesRange(); Review comment: Merging all of them might bring more time or memory cost. For example: - `isIndicesSorted()` can return false as soon as it founds reversed indices, which means its time complexity is almost `O(1)`. Merging this process with `checkSizeAndIndicesRange()` will make this check run in `O(n)` time complexity. - If `checkDuplicatedIndices` is executed on an unsorted array, we will need an additional set to store all history indices, which brings `O(n)` memory cost. Except the conditions above, I agree that `checkSizeAndIndicesRange()` and `checkDuplicatedIndices` can be merged to one function. I'll change the code in this way. -- 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]
