package com.imsl.test.example.stat;

import com.imsl.stat.PooledCovariances;
import com.imsl.math.PrintMatrix;
/**
 * <p>Computes a pooled variance-covariance matrix involving 2 groups.</p>
 * 
 * @see <a href="PooledCovariancesEx1.java">Code</a>
 * @see <a href="doc-files/PooledCovariancesEx1.out">Output</a>
 */

public class PooledCovariancesEx1 {

    static public void main(String arg[]) {
        double[][] x = {
            {2.2, 5.6}, {3.4, 2.3}, {1.2, 7.8},
            {3.2, 2.1}, {4.1, 1.6}, {3.7, 2.2}
        };
        int[] groups = {1, 1, 1, 2, 2, 2};
        int nGroups = 2;

        PooledCovariances pc = new PooledCovariances(nGroups);
        pc.update(x, groups);

        double covar[][] = pc.getPooledCovariances();
        new PrintMatrix("Pooled Covariances").print(covar);
    }
}