| /* |
| * 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.commons.math4.legacy.stat.descriptive.moment; |
| |
| import java.util.Arrays; |
| |
| import org.apache.commons.math4.legacy.exception.DimensionMismatchException; |
| |
| /** |
| * Returns the arithmetic mean of the available vectors. |
| * @since 1.2 |
| */ |
| public class VectorialMean { |
| /** Means for each component. */ |
| private final Mean[] means; |
| |
| /** Constructs a VectorialMean. |
| * @param dimension vectors dimension |
| */ |
| public VectorialMean(int dimension) { |
| means = new Mean[dimension]; |
| for (int i = 0; i < dimension; ++i) { |
| means[i] = new Mean(); |
| } |
| } |
| |
| /** |
| * Add a new vector to the sample. |
| * @param v vector to add |
| * @throws DimensionMismatchException if the vector does not have the right dimension |
| */ |
| public void increment(double[] v) throws DimensionMismatchException { |
| if (v.length != means.length) { |
| throw new DimensionMismatchException(v.length, means.length); |
| } |
| for (int i = 0; i < v.length; ++i) { |
| means[i].increment(v[i]); |
| } |
| } |
| |
| /** |
| * Get the mean vector. |
| * @return mean vector |
| */ |
| public double[] getResult() { |
| double[] result = new double[means.length]; |
| for (int i = 0; i < result.length; ++i) { |
| result[i] = means[i].getResult(); |
| } |
| return result; |
| } |
| |
| /** |
| * Get the number of vectors in the sample. |
| * @return number of vectors in the sample |
| */ |
| public long getN() { |
| return (means.length == 0) ? 0 : means[0].getN(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public int hashCode() { |
| final int prime = 31; |
| int result = 1; |
| result = prime * result + Arrays.hashCode(means); |
| return result; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean equals(Object obj) { |
| if (this == obj) { |
| return true; |
| } |
| if (!(obj instanceof VectorialMean)) { |
| return false; |
| } |
| VectorialMean other = (VectorialMean) obj; |
| return Arrays.equals(means, other.means); |
| } |
| |
| } |