| /* |
| * 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.datasketches.quantiles; |
| |
| import org.apache.datasketches.memory.WritableMemory; |
| |
| /** |
| * For building a new DoublesSketch Union operation. |
| * |
| * @author Lee Rhodes |
| */ |
| public class DoublesUnionBuilder { |
| private int bMaxK = PreambleUtil.DEFAULT_K; |
| |
| /** |
| * Constructor for a new DoublesUnionBuilder. The default configuration is |
| * <ul> |
| * <li>k: 128. This produces a normalized rank error of about 1.7%</li> |
| * <li>Memory: null</li> |
| * </ul> |
| */ |
| public DoublesUnionBuilder() {} |
| |
| /** |
| * Sets the parameter <i>masK</i> that determines the maximum size of the sketch that |
| * results from a union and its accuracy. |
| * @param maxK determines the accuracy and size of the union and is a maximum value. |
| * The effective <i>k</i> can be smaller due to unions with smaller <i>k</i> sketches. |
| * It is recommended that <i>maxK</i> be a power of 2 to enable unioning of sketches with |
| * different values of <i>k</i>. |
| * @return this builder |
| */ |
| public DoublesUnionBuilder setMaxK(final int maxK) { |
| Util.checkK(maxK); |
| bMaxK = maxK; |
| return this; |
| } |
| |
| /** |
| * Gets the current configured value of <i>maxK</i> |
| * @return the current configured value of <i>maxK</i> |
| */ |
| public int getMaxK() { |
| return bMaxK; |
| } |
| |
| /** |
| * Returns a new empty Union object with the current configuration of this Builder. |
| * @return a Union object |
| */ |
| public DoublesUnion build() { |
| return DoublesUnionImpl.heapInstance(bMaxK); |
| } |
| |
| /** |
| * Returns a new empty Union object with the current configuration of this Builder |
| * and the specified backing destination Memory store. |
| * @param dstMem the destination memory |
| * @return a Union object |
| */ |
| public DoublesUnion build(final WritableMemory dstMem) { |
| return DoublesUnionImpl.directInstance(bMaxK, dstMem); |
| } |
| |
| } |