org.uncertml.statistic.CovarianceMatrix.java Source code

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Here is the source code for org.uncertml.statistic.CovarianceMatrix.java

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/**
 * Copyright 2014 52North Initiative for Geospatial Open Source Software GmbH
 *
 * Licensed 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.uncertml.statistic;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.apache.commons.lang.ArrayUtils;
import org.uncertml.util.Validate;

/**
 * Class representing a covariance matrix.
 * 
 * {@URL https://wiki.aston.ac.uk/foswiki/bin/view/UncertWeb/CovarianceMatrix}
 * 
 * @author Matthew Williams
 * @version 2.0
 */
public class CovarianceMatrix implements IStatistic {

    private int dimension;
    private List<Double> values;

    /**
     * Constructor that takes a dimension and an array of values. There should be
     * dimension^2 values in the covariance matrix.
     * 
     * @param dimension the dimension of the covariance matrix.
     * @param values the values of the covariance matrix.
     */
    public CovarianceMatrix(int dimension, double[] values) {
        this(dimension, Arrays.asList(ArrayUtils.toObject(values)));
    }

    /**
     * Constructor that takes a dimension and a <code>List</code> of values. There should be
     * dimension^2 values in the covariance matrix.
     * 
     * @param dimension the dimension of the covariance matrix.
     * @param values the values of the covariance matrix.
     */
    public CovarianceMatrix(int dimension, List<Double> values) {

        Validate.notNull(values);
        Validate.noNullElements(values);
        Validate.isTrue(dimension > 0);
        Validate.isTrue(dimension * dimension == values.size(),
                "There should be n^2 values in the covariance matrix where n is the dimension");

        this.dimension = dimension;
        this.values = new ArrayList<Double>(values);
    }

    /**
     * 
     * @return the dimension of the covariance matrix.
     */
    public int getDimension() {
        return dimension;
    }

    /**
     * 
     * @return the values of the covariance matrix.
     */
    public List<Double> getValues() {
        return values;
    }

}