JFreeChart显示三个点(...)代替X轴上的值 [英] JFreeChart displaying three dots (...) in place of the values on the X axis

问题描述

我试图绘制一个简单的折线图，并且几乎一切都很好，我在数据集中填充了一个简单的代码，如下所示:

I am trying to plot a simple line chart and almost everything is fine, I am populating my dataset with a simple code like this:

DefaultCategoryDataset dataset = new DefaultCategoryDataset();
dataset.addValue(-10 , "S21" , "1000" );
dataset.addValue(-20 , "S21" , "1001" );
dataset.addValue(-25 , "S21" , "1002" );
dataset.addValue(-30 , "S21" , "1003" );
dataset.addValue(-25 , "S21" , "1004" );
...

然后我创建一个折线图:

then I create a line chart:

lineChart = ChartFactory.createLineChart(
    "S21",
    "Frequency (MHz)",
    "Value (db)",
    dataset,
    PlotOrientation.VERTICAL,
    true,
    true,
    false);

，我在X轴上的值为1000 1001 1002 ...等.无论如何，我注意到，如果再添​​加一些点，则jfreechart在x轴上没有足够的空间，并显示三个点(...). )代替值.这很奇怪，我想获得尽可能多的积分(例如1000， 分辨率)，但标签仅针对这些点的子集显示，因此我不会用完od空间:

and I have on the X axis the values 1000 1001 1002 ... etc. Anyway I noticed that, if I add some more points, jfreechart does not have enough space on the x axis and displays three dots (...) in the place of the values. This is pretty weird, I would like to have as many points as I like (e.g. 1000, to have a good resolution) but the labels shown only for a subset of these points, so I do not run out od space:

例如点:1000、1001、1002，...，2000(1000点)

E.g. points: 1000, 1001, 1002, ..., 2000 (1000 points)

标签:1000、1100、1200，...，1900、2000(10个标签)

Labels: 1000, 1100, 1200, ..., 1900, 2000 (10 labels)

有可能吗?我在网上寻找解决方案，但没有发现任何有用的方法.

Is it possible? I looked for a solution on the net, but didn't find anything useful.

推荐答案

您可能必须结合几种方法:

You may have to combine several approaches:

• 按建议在此处更改CategoryLabelPositions.

CategoryAxis domainAxis = plot.getDomainAxis();
domainAxis.setCategoryLabelPositions(
    CategoryLabelPositions.createUpRotationLabelPositions(Math.PI / 2.0));

按照建议的此处调整图表的大小.

Adjust the chart's size, as suggested here.

ChartPanel piePanel = new ChartPanel(lineChart) {
    @Override
    public Dimension getPreferredSize() {
        return new Dimension(640, 480);
    }
};

(可选)，根据类别的数量，使用SlidingCategoryDataset，如此处所示.

Optionally, depending on the number of categories, use a SlidingCategoryDataset, as suggested here.

(可选)如果类别构成一个连续域，请切换到XY图，例如ChartFactory.createXYLineChart().

Optionally, if the categories form a continuous domain, switch to an XY plot, e.g. ChartFactory.createXYLineChart().

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