package com.imsl.test.example.stat;

import com.imsl.stat.*;
/**
 * <p>Computes a lagged difference formula for the airline data excluding
 * the lost observations.</p>
 * 
 * <p>This example uses the same data as {@link DifferenceEx1}. The first number 
of lost observations are excluded from \(W\) due to differencing, 
and the number of lost observations is also output.</p>  

 * @see <a href="DifferenceEx2.java">Code</a>
 * @see <a href="doc-files/DifferenceEx2.out">Output</a>
 */

public class DifferenceEx2 {

    public static void main(String args[]) {
        int periods[] = {1, 12};
        int nLost;
        double[] z = {
            112.0, 118.0, 132.0, 129.0, 121.0, 135.0,
            148.0, 148.0, 136.0, 119.0, 104.0, 118.0,
            115.0, 126.0, 141.0, 135.0, 125.0, 149.0,
            170.0, 170.0, 158.00, 133.0, 114.0, 140.0
        };

        Difference diff = new Difference();
        diff.excludeFirst(true);
        double[] out = diff.compute(z, periods);
        nLost = diff.getObservationsLost();

        System.out.println("The number of observation lost = " + nLost);
        for (int i = 0; i < out.length; i++) {
            System.out.println(out[i]);
        }
    }
}