将XYPlot的日期轴缩放到固定间隔 [英] Scale date axis of XYPlot to a fixed interval

问题描述

在Java项目中，我使用了JFreeChart 1.0.19版本和XYPlot在绘图上绘制线条.

我希望将比例尺xAxis(日期轴)作为日期，例如-10:00:05、10:00:05、10:00:10、10:00:15…-每5秒缩放一次. /p>

但是现在，当用户以10:00:03时间开始时，它看起来像是10:00:03、10:00:08、10:00:13、10:00:18…

我希望始终将5秒缩放为10:00:05、10:00:05、10:00:10、10:00:15，并且与开始时间无关，如何设置?

我将域轴(时间轴)配置如下:

domainAxis.setAutoRange(true);
domainAxis.setAutoTickUnitSelection(true);
domainAxis.setLowerMargin(0.001);
domainAxis.setUpperMargin(0.001);

domainAxis是ValueAxis

的对象

我的情节看起来像 如您所见，时间值是11:21:57、11:22:07、11:22:17等.我希望始终应该是11:21:55、11:22:05、11:22:15等

解决方案

因为domainAxis是

In Java project, I used JFreeChart 1.0.19 version and XYPlot to draw lines on plot.

I want scale xAxis (Date axis) as date in example - 10:00:05, 10:00:05, 10:00:10, 10:00:15…—scaling for every 5 seconds.

But now when user start with 10:00:03 time, it looks as 10:00:03, 10:00:08, 10:00:13, 10:00:18…

I want that always be scaled of 5 seconds as 10:00:05, 10:00:05, 10:00:10, 10:00:15 and be independently of start time, how to set it?

I configurated domain axis(time axis) as below:

domainAxis.setAutoRange(true);
domainAxis.setAutoTickUnitSelection(true);
domainAxis.setLowerMargin(0.001);
domainAxis.setUpperMargin(0.001);

domainAxis is a object of ValueAxis

My plot looks like as You see the time values are 11:21:57, 11:22:07, 11:22:17 etc. I want that always should be 11:21:55, 11:22:05, 11:22:15 etc.

解决方案

Because domainAxis is an instance of DateAxis, you can use setTickUnit() to specify a DateTickUnit having the desired unitType and multiple. In this fragment, the interval is five seconds, and the format includes seconds:

domainAxis.setTickUnit(new DateTickUnit(DateTickUnitType.SECOND, 5));
domainAxis.setDateFormatOverride(new SimpleDateFormat("HH:mm:ss"));

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