JFreeChart 饼图
JFreeChart-Pie Chart
饼图是一个圆形图，它被分成多个扇区，其中每个扇区的面积代表数据的大小。
下图显示了一些包含在 JFreeChart 库中的饼图演示版本:
饼图演示 1:
饼图演示 2:
饼图演示 4:
饼图示例
让我们考虑一个班级分数分布的样本数据。
| 标记范围 |
学生人数 |
| 80-100 |
120 |
| 60-79 |
80 |
| 40-59 |
20 |
| 20-39 |
7 |
| 0-19 |
3 |
以下代码根据上述示例数据创建饼图:
PieChartExample.java
import java.text.DecimalFormat;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.labels.PieSectionLabelGenerator;
import org.jfree.chart.labels.StandardPieSectionLabelGenerator;
import org.jfree.chart.plot.PiePlot;
import org.jfree.data.general.DefaultPieDataset;
import org.jfree.data.general.PieDataset;
public class PieChartExample extends JFrame {
private static final long serialVersionUID = 6294689542092367723L;
public PieChartExample(String title) {
super(title);
// Create dataset
PieDataset dataset = createDataset();
// Create chart
JFreeChart chart = ChartFactory.createPieChart(
"Pie Chart Example",
dataset,
true,
true,
false);
//Format Label
PieSectionLabelGenerator labelGenerator = new StandardPieSectionLabelGenerator(
"Marks {0} : ({2})", new DecimalFormat("0"), new DecimalFormat("0%"));
((PiePlot) chart.getPlot()).setLabelGenerator(labelGenerator);
// Create Panel
ChartPanel panel = new ChartPanel(chart);
setContentPane(panel);
}
private PieDataset createDataset() {
DefaultPieDataset dataset=new DefaultPieDataset();
dataset.setValue("80-100", 120);
dataset.setValue("60-79", 80);
dataset.setValue("40-59", 20);
dataset.setValue("20-39", 7);
dataset.setValue("0-19", 3);
return dataset;
}
public static void main(String[] args) {
SwingUtilities.invokeLater(()-> {
PieChartExample example = new PieChartExample(?Pie Chart Example?);
example.setSize(800, 400);
example.setLocationRelativeTo(null);
example.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
example.setVisible(true);
});
}
}
输出:
