package com.imsl.test.example.stat;

import com.imsl.stat.*;

/**
 * <p>
 * Performs a hypothesis test for the mean of a normal distribution.
 * </p>
 * <p>
 * This example uses data from Devore (1982, p335), which is based on data
 * published in the <i>Journal of Materials</i>. There are \(15\) observations.
 * The hypothesis \(H_0: \mu = 20.0\) is tested. The extremely large
 * <i>t</i> value and the correspondingly small <i>p</i>-value provide strong
 * evidence to reject the null hypothesis.</p>
 *
 *
 * @see <a href="NormOneSampleEx1.java">Code</a>
 * @see <a href="doc-files/NormOneSampleEx1.out">Output</a>
 */
public class NormOneSampleEx1 {

    public static void main(String args[]) {
        double mean, stdev, lomean, upmean, t, pvalue;
        int df;
        double[] x = {
            26.7, 25.8, 24.0, 24.9, 26.4,
            25.9, 24.4, 21.7, 24.1, 25.9,
            27.3, 26.9, 27.3, 24.8, 23.6
        };

        /* Perform Analysis*/
        NormOneSample n1samp = new NormOneSample(x);

        mean = n1samp.getMean();
        stdev = n1samp.getStdDev();
        lomean = n1samp.getLowerCIMean();
        upmean = n1samp.getUpperCIMean();
        n1samp.setTTestNull(20.0);
        df = n1samp.getTTestDF();
        t = n1samp.getTTest();
        pvalue = n1samp.getTTestP();

        /* Print results */
        System.out.println("Sample Mean = " + mean);
        System.out.println("Sample Standard Deviation = " + stdev);
        System.out.println("95% CI for the mean is " + lomean + "   " + upmean);
        System.out.println("T Test results");
        System.out.println("df = " + df);
        System.out.println("t = " + t);
        System.out.println("pvalue = " + pvalue);
        System.out.println("");

        /* CI variance */
        double ciLoVar = n1samp.getLowerCIVariance();
        double ciUpVar = n1samp.getUpperCIVariance();
        System.out.println("CI variance is " + ciLoVar + "    " + ciUpVar);
        /*chi-squared test */
        df = n1samp.getChiSquaredTestDF();
        t = n1samp.getChiSquaredTest();
        pvalue = n1samp.getChiSquaredTestP();
        System.out.println("Chi-squared Test results");
        System.out.println("Chi-squared df = " + df);
        System.out.println("Chi-squared t = " + t);
        System.out.println("Chi-squared pvalue = " + pvalue);
    }
}