获取缩放散点图中的面积或元素

Question

我有以下问题。我想放大散点图，然后选择所有显示的元素。

以某种方式获得放大散点图中的显示区域就足够了。从该区域的范围我可以确定哪些元素显示在该区域中，哪些不显示。

\edit：找到解决方案（实现 AxisChangeListener 接口）

import java.awt.Color;
import java.awt.Dimension;

import org.jfree.chart.ChartPanel;
import org.jfree.chart.event.AxisChangeEvent;
import org.jfree.chart.event.AxisChangeListener;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.XYPlot;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;
import org.jfree.ui.ApplicationFrame;
import org.jfree.ui.RefineryUtilities;
import org.jfree.chart.ChartFactory;  
import org.jfree.chart.JFreeChart; 


public class ScatterExample extends ApplicationFrame implements AxisChangeListener {
/**
 * Creates a new demo instance.
 * @param title the frame title. 
 */

private XYSeriesCollection dataset;
private JFreeChart chart;


public ScatterExample(String title) { 
    super(title);

    dataset = createSampleXYDataset();

    chart = ChartFactory.createScatterPlot(
            "Scatterplot Demo", // chart title
            "X", // domain axis label
            "Y", // range axis label
            dataset,  // data
            PlotOrientation.VERTICAL, // orientation
            true, // include legend
            true, // tooltips? 
            false // URLs?

    ); 
    //customize chart
    chart.setBackgroundPaint(Color.white); 
    XYPlot plot = chart.getXYPlot(); 
    plot.setBackgroundPaint(Color.lightGray); 
    plot.setRangeGridlinePaint(Color.white);

    plot.getRangeAxis().setRange(0.0, 10.0);
    plot.getRangeAxis().addChangeListener(this);
    plot.getDomainAxis().setRange(0.0, 10.0);
    plot.getDomainAxis().addChangeListener(this);

    ChartPanel chartPanel = new ChartPanel(chart, false); 
    chartPanel.setPreferredSize(new Dimension(500, 500)); 
    setContentPane(chartPanel); 
}

private XYSeriesCollection createSampleXYDataset() {
    XYSeriesCollection d = new XYSeriesCollection();
    XYSeries ser = new XYSeries("Series 1");
    XYSeries ser2 = new XYSeries("Series 2");

    ser.add(1.0,2.0);
    ser.add(2.0,2.0);
    ser2.add(3.0,2.0);
    ser.add(3.0,3.0);
    ser2.add(2.0,5.0);
    ser.add(1.0,2.0);
    ser.add(3.0,7.0);
    ser2.add(4.0,4.0);

    d.addSeries(ser);
    d.addSeries(ser2);

    return d;
}

/**
 * Starting point for the demonstration application. 
 * @param args ignored. 
 */

public static void main(String[] args) {
    ScatterExample demo = new ScatterExample("Scatterplot Demo"); 
    demo.pack(); 
    RefineryUtilities.centerFrameOnScreen(demo); 
    demo.setVisible(true);
}

@Override
public void axisChanged(AxisChangeEvent event) {
    if (event.getAxis().equals(chart.getXYPlot().getRangeAxis())){
        double rangeLow = chart.getXYPlot().getRangeAxis().getLowerBound();
        double rangeUp = chart.getXYPlot().getRangeAxis().getUpperBound();

        System.out.println("RangeAxis new range from "+rangeLow+" to "+rangeUp);
    }
    else {
        if (event.getAxis().equals(chart.getXYPlot().getDomainAxis())){
            double domainLow = chart.getXYPlot().getDomainAxis().getLowerBound();
            double domainUp = chart.getXYPlot().getDomainAxis().getUpperBound();

            System.out.println("DomainAxis new range from "+domainLow+" to "+domainUp);
        }
    }   
}
}

Answer 1

发布者通过让 ScatterExample 类实现 AxisChangeListener< 找到了解决方案/代码> 接口。 示例已更新为版本 1.5。它还添加了一个表格来显示轴边界更改的历史记录。该图像显示了缩放、平移并单击缩放命令按钮放大的结果重置 Y。

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Rectangle;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JToolBar;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.DefaultTableModel;

import org.jfree.chart.ChartPanel;
import org.jfree.chart.event.AxisChangeEvent;
import org.jfree.chart.event.AxisChangeListener;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.XYPlot;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;
import org.jfree.chart.ChartFactory;
import static org.jfree.chart.ChartPanel.*;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.Axis;
import org.jfree.chart.axis.ValueAxis;

public final class ScatterExample implements AxisChangeListener {

    private static final int N = 32; // data points per series
    private static final int R = 10; // initial axis bounds
    private final Random RANDOM = new Random();
    private ChartPanel chartPanel = new ChartPanel(null, false) {
        @Override
        public Dimension getPreferredSize() {
            return new Dimension(400, 400);
        }
    };
    private final DefaultTableModel model = new DefaultTableModel(
        new String[]{"Axis", "lower bound", "upper bound"}, 0) {
        @Override
        public boolean isCellEditable(int row, int column) {
            return false;
        }
    };
    private final JTable table = new JTable(model) {

        @Override
        public Class<?> getColumnClass(int column) {
            switch (column) {
                case 0:
                    return String.class;
                case 1:
                    return Double.class;
                case 2:
                    return Double.class;
                default:
                    return String.class;
            }
        }

        @Override
        public Dimension getPreferredScrollableViewportSize() {
            return new Dimension(250, 400);
        }
    };

    public static void main(String[] args) {
        EventQueue.invokeLater(new ScatterExample()::display);
    }

    private void display() {
        XYSeriesCollection dataset = createSampleXYDataset();
        JFreeChart chart = ChartFactory.createScatterPlot(
            "Scatterplot", // chart title
            "X", // domain axis label
            "Y", // range axis label
            dataset, // data
            PlotOrientation.VERTICAL, // orientation
            true, // include legend?
            true, // tooltips? 
            false // URLs?
        );
        XYPlot plot = chart.getXYPlot();
        plot.setDomainPannable(true);
        plot.getDomainAxis().setRange(-R, R);
        plot.getDomainAxis().addChangeListener(this);
        plot.setRangePannable(true);
        plot.getRangeAxis().setRange(-R, R);
        plot.getRangeAxis().addChangeListener(this);

        chartPanel.setChart(chart);
        table.setDefaultRenderer(Double.class, new DefaultTableCellRenderer() {
            {
                setHorizontalAlignment(JLabel.RIGHT);
            }
            NumberFormat f = new DecimalFormat("#.00");

            @Override
            protected void setValue(Object value) {
                setText((value == null) ? "" : f.format(value));
            }
        });

        JFrame f = new JFrame("Axis Range Example");
        f.add(chartPanel);
        f.add(createControls(), BorderLayout.SOUTH);
        f.add(new JScrollPane(table), BorderLayout.EAST);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    private XYSeriesCollection createSampleXYDataset() {
        XYSeriesCollection d = new XYSeriesCollection();
        XYSeries series1 = new XYSeries("Series 1");
        XYSeries series2 = new XYSeries("Series 2");
        for (int i = 0; i < N; i++) {
            series1.add(RANDOM.nextGaussian(), RANDOM.nextGaussian());
            series2.add(RANDOM.nextGaussian(), RANDOM.nextGaussian());
        }
        d.addSeries(series1);
        d.addSeries(series2);
        return d;
    }

    @Override
    public void axisChanged(AxisChangeEvent event) {
        Axis changed = event.getAxis();
        ValueAxis domainAxis = chartPanel.getChart().getXYPlot().getDomainAxis();
        ValueAxis rangeAxis = chartPanel.getChart().getXYPlot().getRangeAxis();
        if (changed.equals(domainAxis)) {
            double lower = domainAxis.getLowerBound();
            double upper = domainAxis.getUpperBound();
            model.addRow(new Object[]{"Domain", lower, upper});
        }
        if (changed.equals(rangeAxis)) {
            double lower = rangeAxis.getLowerBound();
            double upper = rangeAxis.getUpperBound();
            model.addRow(new Object[]{"Range", lower, upper});
        }
        int last = table.getModel().getRowCount() - 1;
        Rectangle r = table.getCellRect(last, 0, true);
        table.scrollRectToVisible(r);
    }

    // @see https://stackoverflow.com/a/41544007/230513
    private JPanel createControls() {
        JPanel panel = new JPanel();
        JToolBar toolBar = new JToolBar();
        toolBar.add(createButton("Zoom In", ZOOM_IN_BOTH_COMMAND));
        toolBar.add(createButton("Zoom In X", ZOOM_IN_DOMAIN_COMMAND));
        toolBar.add(createButton("Zoom In Y", ZOOM_IN_RANGE_COMMAND));
        toolBar.add(createButton("Zoom Out", ZOOM_OUT_BOTH_COMMAND));
        toolBar.add(createButton("Zoom Out X", ZOOM_OUT_DOMAIN_COMMAND));
        toolBar.add(createButton("Zoom Out Y", ZOOM_OUT_RANGE_COMMAND));
        toolBar.add(createButton("Reset", ZOOM_RESET_BOTH_COMMAND));
        toolBar.add(createButton("Reset X", ZOOM_RESET_DOMAIN_COMMAND));
        toolBar.add(createButton("Reset Y", ZOOM_RESET_RANGE_COMMAND));
        panel.add(toolBar);
        return panel;
    }

    private JButton createButton(String name, String command) {
        final JButton b = new JButton(name);
        b.setActionCommand(command);
        b.addActionListener(chartPanel);
        return b;
    }
}