de.uniwuerzburg.info3.ofcprobe.vswitch.trafficgen.IATGen.java Source code

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Here is the source code for de.uniwuerzburg.info3.ofcprobe.vswitch.trafficgen.IATGen.java

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/*
 * Copyright (C) 2014 Christopher Metter
 *
 * 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, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package de.uniwuerzburg.info3.ofcprobe.vswitch.trafficgen;

import org.apache.commons.math3.distribution.AbstractRealDistribution;
import org.apache.commons.math3.distribution.ChiSquaredDistribution;
import org.apache.commons.math3.distribution.ExponentialDistribution;
import org.apache.commons.math3.distribution.GammaDistribution;
import org.apache.commons.math3.distribution.IntegerDistribution;
import org.apache.commons.math3.distribution.NormalDistribution;
import org.apache.commons.math3.distribution.PoissonDistribution;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * This Class generates random IAT values after a Set Distribution
 *
 * @author Christopher Metter(christopher.metter@informatik.uni-wuerzburg.de)
 *
 */
public class IATGen {

    /**
     * Debugger
     */
    private static final Logger logger = LoggerFactory.getLogger(IATGen.class);
    /**
     * The Distri
     */
    private AbstractRealDistribution distri;
    /**
     * The other Distri
     */
    private IntegerDistribution intDistri;

    /**
     * Constructor
     *
     * @param distribution Distribution as String
     * @param para1 Parameter 1
     * @param para2 Parameter 2 (only needed when applicable)
     */
    public IATGen(String distribution, double para1, double para2) {

        logger.trace("Distribution selected: {} with Parameters {} & {}", distribution, para1, para2);

        switch (distribution) {
        case "ChiSquared":
            this.distri = new ChiSquaredDistribution(para1);
            break;
        case "Exponential":
            this.distri = new ExponentialDistribution(para1);
            break;
        case "Gamma":
            this.distri = new GammaDistribution(para1, para2);
            break;
        case "Poisson":
            this.intDistri = new PoissonDistribution(para1, para2);
            break;
        default:
            this.distri = new NormalDistribution(para1, para2);
            break;
        }
    }

    /**
     * Gets the next IAT after set Distribution
     *
     * @return next IAT
     */
    public int nextIAT() {
        if (this.distri != null) {
            double sample = this.distri.sample();
            if (sample < 0) {
                sample = sample * -1;
            }
            logger.trace("New SampleValue: {}", (int) sample);
            return (int) sample;
        }

        int sample = this.intDistri.sample();
        if (sample < 0) {
            sample = sample * -1;
        }
        logger.trace("New SampleValue: {}", sample);
        return sample;

    }

}