我想在TimeSeries图表上显示实时数据,其中实时显示在x轴上(或者至少具有与实时相同的时间速度)。
这是问题的SSCCE,随机数作为实时输入。 x轴上显示的时间比实时快得多(假设它以hh:mm:ss格式显示):
public class DynamicTimeSeriesChart extends JPanel {
private DynamicTimeSeriesCollection dataset;
private JFreeChart chart = null;
public DynamicTimeSeriesChart(final String title) {
dataset = new DynamicTimeSeriesCollection(1, 2000, new Second());
dataset.setTimeBase(new Second(0, 0, 0, 1, 1, 1990)); // date 1st jan 0 mins 0 secs
dataset.addSeries(new float[1], 0, title);
chart = ChartFactory.createTimeSeriesChart(
title, "Time", title, dataset, true,
true, false);
final XYPlot plot = chart.getXYPlot();
ValueAxis axis = plot.getDomainAxis();
axis.setAutoRange(true);
axis.setFixedAutoRange(200000); // proportional to scroll speed
axis = plot.getRangeAxis();
final ChartPanel chartPanel = new ChartPanel(chart);
setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
add(chartPanel);
}
public void update(float value) {
float[] newData = new float[1];
newData[0] = value;
dataset.advanceTime();
dataset.appendData(newData);
}
public static void main(String[] args) {
JFrame frame = new JFrame("testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final DynamicTimeSeriesChart chart = new DynamicTimeSeriesChart("random numbers");
frame.add(chart);
frame.pack();
frame.setVisible(true);
Timer timer = new Timer(100, new ActionListener() {
public void actionPerformed(ActionEvent e) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
chart.update((float) (Math.random() * 10));
}
});
}
});
timer.start();
}
}
答案 0 :(得分:4)
虽然initial thread上的sleep()
可以接受,但应该在事件派发线程上构造和操作仅的Swing GUI对象。相反,使用javax.swing.Timer
来调整更新速度,如here所示。 delay
的100毫秒将以大约10赫兹的速度更新。
如果漂移是不可接受的,则以另一个线程以标称速率的一半轮询主机的时钟,并使用EventQueue.invokeLater()
更新数据集。确保主机已同步到NTP服务器。
附录:根据您的更新,请注意所有 Swing GUI对象必须在事件派发线程上仅构建和操作,而不仅仅是javax.swing.Timer
。 Swing Timer
的优势在于它在EDT上发射。下面的变化显示了近似实时的10秒1 Hz数据。
附录:您可以调整setTimeBase()
所显示的时间here。
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.SimpleDateFormat;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.DateAxis;
import org.jfree.chart.plot.XYPlot;
import org.jfree.data.time.DynamicTimeSeriesCollection;
import org.jfree.data.time.Second;
/**
* @see https://stackoverflow.com/a/21307289/230513
*/
public class DynamicTimeSeriesChart extends JPanel {
private final DynamicTimeSeriesCollection dataset;
private final JFreeChart chart;
public DynamicTimeSeriesChart(final String title) {
dataset = new DynamicTimeSeriesCollection(1, 1000, new Second());
dataset.setTimeBase(new Second(0, 0, 0, 23, 1, 2014));
dataset.addSeries(new float[1], 0, title);
chart = ChartFactory.createTimeSeriesChart(
title, "Time", title, dataset, true, true, false);
final XYPlot plot = chart.getXYPlot();
DateAxis axis = (DateAxis) plot.getDomainAxis();
axis.setFixedAutoRange(10000);
axis.setDateFormatOverride(new SimpleDateFormat("ss.SS"));
final ChartPanel chartPanel = new ChartPanel(chart);
add(chartPanel);
}
public void update(float value) {
float[] newData = new float[1];
newData[0] = value;
dataset.advanceTime();
dataset.appendData(newData);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
JFrame frame = new JFrame("testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final DynamicTimeSeriesChart chart
= new DynamicTimeSeriesChart("Alternating data");
frame.add(chart);
frame.pack();
Timer timer = new Timer(1000, new ActionListener() {
private boolean b;
@Override
public void actionPerformed(ActionEvent e) {
chart.update(b ? 1 : 0);
b = !b;
}
});
timer.start();
frame.setVisible(true);
}
});
}
}