jat.examples.TwoBodyExample.TwoBodyExample.java Source code

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Here is the source code for jat.examples.TwoBodyExample.TwoBodyExample.java

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/* JAT: Java Astrodynamics Toolkit
 * 
  Copyright 2012 Tobias Berthold
    
   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at
    
   http://www.apache.org/licenses/LICENSE-2.0
    
   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
 */

package jat.examples.TwoBodyExample;

import jat.core.cm.TwoBodyAPL;
import jat.core.plot.plot.FrameView;
import jat.core.plot.plot.Plot2DPanel;
import jat.core.plot.plot.PlotPanel;
import jat.core.plot.plot.plots.ScatterPlot;

import java.awt.Color;
import java.text.DecimalFormat;

import javax.swing.JFrame;

import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.math3.linear.ArrayRealVector;
import org.apache.commons.math3.linear.RealVectorFormat;
import org.apache.commons.math3.ode.FirstOrderIntegrator;
import org.apache.commons.math3.ode.nonstiff.DormandPrince853Integrator;

public class TwoBodyExample {

    public TwoBodyExample() {
    }

    public static void main(String[] args) {

        TwoBodyExample x = new TwoBodyExample();

        // create a TwoBody orbit using orbit elements
        TwoBodyAPL sat = new TwoBodyAPL(7000.0, 0.3, 0.0, 0.0, 0.0, 0.0);

        double[] y = sat.randv();

        ArrayRealVector v = new ArrayRealVector(y);

        DecimalFormat df2 = new DecimalFormat("#,###,###,##0.00");
        RealVectorFormat format = new RealVectorFormat(df2);
        System.out.println(format.format(v));

        // find out the period of the orbit
        double period = sat.period();

        // set the final time = one orbit period
        double tf = period;

        // set the initial time to zero
        double t0 = 0.0;

        // propagate the orbit
        FirstOrderIntegrator dp853 = new DormandPrince853Integrator(1.0e-8, 100.0, 1.0e-10, 1.0e-10);
        dp853.addStepHandler(sat.stepHandler);
        // double[] y = new double[] { 7000.0, 0, 0, .0, 8, 0 }; // initial
        // state

        dp853.integrate(sat, 0.0, y, 8000, y); // now y contains final state at
        // tf

        Double[] objArray = sat.time.toArray(new Double[sat.time.size()]);
        double[] timeArray = ArrayUtils.toPrimitive(objArray);
        double[] xsolArray = ArrayUtils.toPrimitive(sat.xsol.toArray(new Double[sat.time.size()]));
        double[] ysolArray = ArrayUtils.toPrimitive(sat.ysol.toArray(new Double[sat.time.size()]));

        double[][] XY = new double[timeArray.length][2];

        // int a=0;
        // System.arraycopy(timeArray,0,XY[a],0,timeArray.length);
        // System.arraycopy(ysolArray,0,XY[1],0,ysolArray.length);

        for (int i = 0; i < timeArray.length; i++) {
            XY[i][0] = xsolArray[i];
            XY[i][1] = ysolArray[i];
        }

        Plot2DPanel p = new Plot2DPanel();

        // Plot2DPanel p = new Plot2DPanel(min, max, axesScales, axesLabels);

        ScatterPlot s = new ScatterPlot("orbit", Color.RED, XY);
        // LinePlot l = new LinePlot("sin", Color.RED, XY);
        // l.closed_curve = false;
        // l.draw_dot = true;
        p.addPlot(s);
        p.setLegendOrientation(PlotPanel.SOUTH);
        double plotSize = 10000.;
        double[] min = { -plotSize, -plotSize };
        double[] max = { plotSize, plotSize };
        p.setFixedBounds(min, max);

        new FrameView(p).setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        System.out.println("end");

    }
}