Your snippet is incorrectly synchronized; you should update your dataset from the process() method of a SwingWorker, as shown here. Because your domain is "the number of my inner iterations", don't use a DateAxis; instead, use a NumberAxis, as shown in ChartFactory.createXYLineChart().
Addendum: This variation on the example plots the worker's progress on a line chart. Note that createXYLineChart() uses NumberAxis for both domain and range. Given a series in the line chart's dataset, note also how the implementation of process() can safely update the dataset as new data arrives; the listening chart will update itself in response.
private XYSeries series = new XYSeries("Result");
…
@Override
protected void process(List<Double> chunks) {
for (double d : chunks) {
label.setText(df.format(d));
series.add(++n, d);
}
}
![chart]()
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.beans.PropertyChangeEvent;
import java.text.DecimalFormat;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JProgressBar;
import javax.swing.SwingWorker;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
import org.jfree.data.xy.XYDataset;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;
/**
* @see https://mcmap.net/q/376794/-random-errors-when-changing-series-using-jfreechart
* @see https://stackoverflow.com/questions/4637215
*/
public final class ChartWorker {
private static final String S = "0.000000000000000";
private final JProgressBar progressBar = new JProgressBar();
private final JLabel label = new JLabel(S, JLabel.CENTER);
private final XYSeries series = new XYSeries("Result");
private final XYDataset dataset = new XYSeriesCollection(series);
private void create() {
JFrame f = new JFrame("√2");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(progressBar, BorderLayout.NORTH);
JFreeChart chart = ChartFactory.createXYLineChart(
"Newton's Method", "X", "Y", dataset,
PlotOrientation.VERTICAL, false, true, false);
XYPlot plot = (XYPlot) chart.getPlot();
plot.getRangeAxis().setRange(1.4, 1.51);
plot.getDomainAxis().setStandardTickUnits(
NumberAxis.createIntegerTickUnits());
XYLineAndShapeRenderer renderer
= (XYLineAndShapeRenderer) plot.getRenderer();
renderer.setSeriesShapesVisible(0, true);
f.add(new ChartPanel(chart) {
@Override
public Dimension getPreferredSize() {
return new Dimension(640, 480);
}
}, BorderLayout.CENTER);
f.add(label, BorderLayout.SOUTH);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
runCalc();
}
private void runCalc() {
progressBar.setIndeterminate(true);
TwoWorker task = new TwoWorker();
task.addPropertyChangeListener((PropertyChangeEvent e) -> {
if ("progress".equals(e.getPropertyName())) {
progressBar.setIndeterminate(false);
progressBar.setValue((Integer) e.getNewValue());
}
});
task.execute();
}
private class TwoWorker extends SwingWorker<Double, Double> {
private static final int N = 5;
private final DecimalFormat df = new DecimalFormat(S);
double x = 1;
private int n;
@Override
protected Double doInBackground() throws Exception {
for (int i = 1; i <= N; i++) {
x = x - (((x * x - 2) / (2 * x)));
setProgress(i * (100 / N));
publish(x);
Thread.sleep(1000); // simulate latency
}
return x;
}
@Override
protected void process(List<Double> chunks) {
for (double d : chunks) {
label.setText(df.format(d));
series.add(++n, d);
}
}
}
public static void main(String[] args) {
EventQueue.invokeLater(new ChartWorker()::create);
}
}
