geogebra.common.kernel.statistics.AlgoZMean2Test.java Source code

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Here is the source code for geogebra.common.kernel.statistics.AlgoZMean2Test.java

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/* 
GeoGebra - Dynamic Mathematics for Everyone
http://www.geogebra.org
    
This file is part of GeoGebra.
    
This program is free software; you can redistribute it and/or modify it 
under the terms of the GNU General Public License as published by 
the Free Software Foundation.
    
 */

package geogebra.common.kernel.statistics;

import geogebra.common.kernel.Construction;
import geogebra.common.kernel.algos.AlgoElement;
import geogebra.common.kernel.commands.Commands;
import geogebra.common.kernel.geos.GeoElement;
import geogebra.common.kernel.geos.GeoList;
import geogebra.common.kernel.geos.GeoNumeric;
import geogebra.common.kernel.geos.GeoText;
import geogebra.common.util.StringUtil;

import org.apache.commons.math.distribution.NormalDistributionImpl;

/**
 * 
 * 
 * @author G. Sturr
 */
public class AlgoZMean2Test extends AlgoElement {

    private GeoNumeric mean, sd, n, mean_2, sd_2, n_2; // input
    private GeoText tail;
    private GeoList list, list2;
    private GeoList result; // output
    private double se;

    /**
     * @param cons
     * @param label
     * @param mean
     * @param sd
     * @param n
     * @param mean_2
     * @param sd_2
     * @param n_2
     * @param tail
     */
    public AlgoZMean2Test(Construction cons, String label, GeoNumeric mean, GeoNumeric sd, GeoNumeric n,
            GeoNumeric mean_2, GeoNumeric sd_2, GeoNumeric n_2, GeoText tail) {
        this(cons, mean, sd, n, mean_2, sd_2, n_2, tail);
        result.setLabel(label);
    }

    /**
     * @param cons
     * @param mean
     * @param sd
     * @param n
     * @param mean_2
     * @param sd_2
     * @param n_2
     * @param tail
     */
    public AlgoZMean2Test(Construction cons, GeoNumeric mean, GeoNumeric sd, GeoNumeric n, GeoNumeric mean_2,
            GeoNumeric sd_2, GeoNumeric n_2, GeoText tail) {
        super(cons);
        this.mean = mean;
        this.sd = sd;
        this.n = n;
        this.mean_2 = mean_2;
        this.sd_2 = sd_2;
        this.n_2 = n_2;
        this.tail = tail;
        result = new GeoList(cons);
        setInputOutput(); // for AlgoElement

        compute();
    }

    /**
     * @param cons
     * @param label
     * @param list
     * @param list2
     * @param sd
     * @param sd_2
     * @param level
     */
    public AlgoZMean2Test(Construction cons, String label, GeoList list, GeoNumeric sd, GeoList list2,
            GeoNumeric sd_2, GeoText tail) {
        super(cons);

        this.list = list;
        this.sd = sd;
        this.list2 = list2;
        this.sd_2 = sd_2;
        this.tail = tail;
        result = new GeoList(cons);
        setInputOutput(); // for AlgoElement

        compute();
        result.setLabel(label);
    }

    @Override
    public Commands getClassName() {
        return Commands.ZMean2Test;
    }

    @Override
    protected void setInputOutput() {

        if (list == null) {
            input = new GeoElement[7];
            input[0] = mean;
            input[1] = sd;
            input[2] = n;
            input[3] = mean_2;
            input[4] = sd_2;
            input[5] = n_2;
            input[6] = tail;
        } else {
            input = new GeoElement[5];
            input[0] = list;
            input[1] = sd;
            input[2] = list2;
            input[3] = sd_2;
            input[4] = tail;
        }

        setOnlyOutput(result);
        setDependencies(); // done by AlgoElement
    }

    /**
     * @return {lower confidence limit, upper confidence limit}.
     */
    public GeoList getResult() {
        return result;
    }

    /**
     * @return standard error
     */
    public double getSE() {
        return se;
    }

    @Override
    public final void compute() {

        String testType;
        if (tail.getTextString().equals("<")) {
            testType = "left";
        } else if (tail.getTextString().equals(">")) {
            testType = "right";
        } else if (StringUtil.isNotEqual(tail.getTextString())) {
            testType = "two";
        } else {
            result.setUndefined();
            return;
        }

        double mean1, mean2;
        double n1, n2;

        double sd1 = sd.getDouble();
        double sd2 = sd_2.getDouble();

        if (list == null) {
            mean1 = mean.getDouble();
            mean2 = mean_2.getDouble();
            n1 = n.getDouble();
            n2 = n_2.getDouble();
        } else {
            mean1 = list.mean();
            n1 = list.size();
            mean2 = list2.mean();
            n2 = list2.size();
        }

        se = Math.sqrt(sd1 * sd1 / n1 + sd2 * sd2 / n2);
        double testStatistic = (mean1 - mean2) / se;

        NormalDistributionImpl normalDist = new NormalDistributionImpl(0, 1);
        double P = 0;
        try {
            P = normalDist.cumulativeProbability(testStatistic);
        } catch (Exception e) {
            result.setUndefined();
            return;
        }

        if ("right".equals(testType)) {
            P = 1 - P;
        } else if ("two".equals(testType)) {
            if (testStatistic < 0) {
                P = 2 * P;
            } else {
                P = 2 * (1 - P);
            }
        }

        // put these results into the output list
        result.clear();
        result.add(new GeoNumeric(cons, P));
        result.add(new GeoNumeric(cons, testStatistic));

    }

}