JFreeChart自定义x轴标签

系列是年：2013,2014,2015等
数据是某一年之内日期+价值。
因为数据需要用年来分类，所以我在x轴上使用“一年中的一天”值，范围在1到366之间。因此给定年份的值如下所示：（1,80），（30100），（60,71）.....（255130）

实施例图：

enter image description here

我的问题是X轴包含 “年度天” 值，但我必须在那里放置月份名称。不幸的是，使用简单的DateAxis不是一种选择，因为X值是日期数字（不是日期），AFAIK没有可以将“335”转换为“December”的日期格式。 DateAxis的另一个问题是它代表时间点，并为任何时间点提供单独的X轴标签。但是我需要写出精确时间点的标签。即：仅在月初。我真正想要的是这样的：

enter image description here

例如而不是在一个月的开始/结束时放置“蜱虫”，我想显示区域。更难的是这几个月有不同的长度。由于2月有闰年29天，我认为我将不得不使用固定点（一年中的某一天值）。

我必须为此编写自定义轴渲染器吗？怎么样？我的问题有更简单的解决方案吗？

来源

2015-04-02 nagylzs

也可以考虑自定义'SymbolAxis'。 – trashgod 2015-04-02 10:09:34

import java.awt.Graphics2D; 
import java.awt.font.LineMetrics; 
import java.awt.geom.Rectangle2D; 
import java.util.List; 
import java.awt.Color; 

import org.jfree.chart.axis.AxisState; 
import org.jfree.chart.axis.NumberAxis; 
import org.jfree.chart.axis.ValueTick; 
import org.jfree.text.TextUtilities; 
import org.jfree.ui.RectangleEdge; 
import org.jfree.ui.TextAnchor; 



public class DayOfYearAxis extends NumberAxis { 
    /* Day of the year values for month end days. */ 
    public static final Integer[] MONTH_LENGTHS = { 
      31,29,31,30,31,30,31,31,30,31,30,31 
    }; 
    public static final String[] MONTH_NAMES = { 
     "Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec" 
}; 

    protected AxisState drawTickMarksAndLabels(Graphics2D g2,double cursor,Rectangle2D plotArea,Rectangle2D dataArea,RectangleEdge edge) { 
     AxisState state = new AxisState(cursor); 

     g2.setFont(getTickLabelFont()); 

     double ol = getTickMarkOutsideLength(); 
     double il = getTickMarkInsideLength(); 
     int y = (int)(Math.round(cursor-ol)); 
     LineMetrics lineMetrics = g2.getFont().getLineMetrics("Ápr", g2.getFontRenderContext());   
     int h = (int) (lineMetrics.getHeight() + 6); 

     List<ValueTick> ticks = refreshTicks(g2, state, dataArea, edge); 
     state.setTicks(ticks); 

     /* Last x point */ 
     ValueTick tick = ticks.get(ticks.size()-1);  
     float[] prevAnchorPoint = calculateAnchorPoint(tick, cursor,dataArea, edge); 
     double xmax = prevAnchorPoint[0]; 
     double max_day = tick.getValue(); 

     /* First x point */ 
     tick = ticks.get(0); 
     prevAnchorPoint = calculateAnchorPoint(tick, cursor,dataArea, edge); 
     double xmin = Math.round(prevAnchorPoint[0]); 
     double min_day = tick.getValue();  
     double days_visible = max_day - min_day + 1; 
     /* 0.1 day horizontal gap. */ 
     double gap = 0.1*(xmax-xmin)/days_visible; 

     System.out.println("min_day "+min_day+" max_day"+max_day); 

     g2.setFont(getTickLabelFont()); 
     g2.setColor(Color.BLACK); 
     int start_day = 0; 
     for (int month=0;month<12;month++) { 
      int end_day = start_day + MONTH_LENGTHS[month] - 1; 
      System.out.println("start-end "+start_day+" "+end_day); 
      if ((start_day>=min_day) && (start_day<=max_day) && (end_day>=min_day) && (end_day<=max_day)) { 
       double factor_x1 = (start_day - min_day)/days_visible; 
       double x1 = xmin + (xmax-xmin)* factor_x1; 
       double factor_x2 = (end_day - min_day)/days_visible; 
       double x2 = xmin + (xmax-xmin)* factor_x2; 
       System.out.println("month="+month+", start_day="+start_day+" end_day="+end_day+" x1="+x1+" x2="+x2); 
       g2.setColor(Color.LIGHT_GRAY); 
       g2.fill3DRect((int)(x1+gap),y,(int)(x2-x1-2*gap),h,true); 
       g2.setColor(Color.BLACK); 
       TextUtilities.drawAlignedString(MONTH_NAMES[month], g2, (float)((x1+x2)/2), (float)(y+ol), TextAnchor.TOP_CENTER); 
      }   
      start_day += MONTH_LENGTHS[month]; 
     } 
     return state; 
    } 

}

用法：

JFreeChart chart = ChartFactory.createXYLineChart(...); 
    DayOfYearAxis doyAxis = new DayOfYearAxis(); 
    /* optional 
    doyAxis.setAutoRange(false); 
    doyAxis.setRange(new Range(min_yday, max_yday)); 
    */ 
    chart.getXYPlot().setDomainAxis(doyAxis);

输出示例（匈牙利月份名称）：

enter image description here

来源

2015-04-02 09:54:30 nagylzs

JFreeChart自定义x轴标签

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