如何設置使用ChartFactory.createBarChart創建的BarGraph的Y軸範圍

Question

我使用以下代碼創建了使用jfree.chart.ChartFactory的條形圖。我需要將Y軸的範圍設置爲0 - 100.如何設置最大值。

import java.io.File; 
import org.jfree.chart.ChartFactory; 
import org.jfree.chart.ChartUtilities; 
import org.jfree.chart.JFreeChart; 
import org.jfree.chart.plot.PlotOrientation; 
import org.jfree.data.category.DefaultCategoryDataset; 

public class BarGraph 
{ 
    public static void main(String[ ] args)throws Exception 
    { 
     final DefaultCategoryDataset dataset = new DefaultCategoryDataset(); 
     dataset.addValue(10 , "FIAT" , "Speed"); 
     dataset.addValue(30 , "AUDI", "Speed"); 
     dataset.addValue(20 , "FORD", "Speed"); 
     dataset.addValue(50 , "BMW", "Speed"); 
     JFreeChart barChart = ChartFactory.createBarChart3D(
      "CAR USAGE STATISTICS", 
      "Category", "Score", 
      dataset,PlotOrientation.VERTICAL, 
      true, true, false); 
     int width = 380; /* Width of the image 480*/ 
     int height = 280; /* Height of the image 360*/ 
     File BarChart = new File("../ELec/WebContent/img/BarChart.jpeg"); 
     ChartUtilities.saveChartAsJPEG(BarChart , barChart , width , height ); 
     } 
    } 

這是我得到的輸出。我需要設置Y軸最大值爲100：對劇情的範圍軸

Answer 1

調用setRange()設置特定範圍，並關閉自動量程：

CategoryPlot plot = (CategoryPlot) barChart.getPlot(); 
NumberAxis rangeAxis = (NumberAxis) plot.getRangeAxis(); 
rangeAxis.setRange(0, 100);