TimeSeries JFreeChart中的XYPointerAnnotation

本文介绍了TimeSeries JFreeChart中的XYPointerAnnotation的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我正在尝试将XYPointerAnnotation实施为TimeSeries图表.但是我不知道，图表如何找到要绘制的y值.代码:

I'm trying to implement XYPointerAnnotation to TimeSeries chart. However I don't know, how does chart finds my y values to plot. Code:

final TimeSeries series = new TimeSeries("asdfas");
Hour hour = new Hour();
series.add(2,hour), 123);
TimeSeriesCollection collection = new TimeSeriesCollection();
collection.addSeries(series);
double temp = Double.parseDouble(
    series1.getTimePeriod(series1.getItemCount()-1).toString());
XYPointerAnnotation pointer1 = new XYPointerAnnotation(
    series1.getValue(series1.getItemCount() - 1).toString(), temp, 00.0);
JFreeChart chart = ChartFactory.createTimeSeriesChart(
    "1", "2", "3", collection, true, true, false);

如何解析从TimeSeries到XYPointerAnnotation的y值?

推荐答案

给出TimeSeries，

TimeSeries series = new TimeSeries("Data");

找到感兴趣的项目，

TimeSeriesDataItem item = series.getDataItem(series.getItemCount() - 1);

根据时间段和值创建注释，

create an annotation based on the period and value,

double x = item.getPeriod().getFirstMillisecond();
double y = item.getValue().doubleValue();
XYPointerAnnotation a = new XYPointerAnnotation("Bam!", x, y, 5 * Math.PI / 8);

并将其添加到绘图中，

XYPlot plot = (XYPlot) chart.getPlot();
plot.addAnnotation(a);

这篇关于TimeSeries JFreeChart中的XYPointerAnnotation的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！