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Diffstat (limited to 'src/main/java/org/apache/commons/math3/stat/descriptive/moment/VectorialMean.java')
-rw-r--r-- | src/main/java/org/apache/commons/math3/stat/descriptive/moment/VectorialMean.java | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/math3/stat/descriptive/moment/VectorialMean.java b/src/main/java/org/apache/commons/math3/stat/descriptive/moment/VectorialMean.java new file mode 100644 index 0000000..e06b3bc --- /dev/null +++ b/src/main/java/org/apache/commons/math3/stat/descriptive/moment/VectorialMean.java @@ -0,0 +1,105 @@ +/* + * 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; + } + +} |