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+/*
+ * 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.math3.stat.descriptive.moment;
+
+import java.io.Serializable;
+import java.util.Arrays;
+
+import org.apache.commons.math3.exception.DimensionMismatchException;
+
+/**
+ * Returns the arithmetic mean of the available vectors.
+ * @since 1.2
+ */
+public class VectorialMean implements Serializable {
+
+ /** Serializable version identifier */
+ private static final long serialVersionUID = 8223009086481006892L;
+
+ /** 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;
+ if (!Arrays.equals(means, other.means)) {
+ return false;
+ }
+ return true;
+ }
+
+}