使用JFreeChart的XYLineAndShapeRenderer绘制自定义线 [英] Draw Custom Lines using JFreeChart's XYLineAndShapeRenderer

问题描述

我有一些逻辑可以用来构建一系列集群.到目前为止，为表示图上每个点所属的群集，我使用了一系列颜色，其中属于同一群集的点具有相同的颜色.

I have some logic which I am using to construct a series of clusters. So far, to denote the cluster to which each point on the graph belongs to, I am using a series of colours, where points belonging to the same cluster are of the same colour.

除此之外，我还想显示每个集群的中心，因为这将帮助我了解集群构建算法的性能.目前，我要通过使用XPointerAnnotation类在图形上编写一些文本.问题在于，我认为将文本放在点上会导致混乱的情节(考虑到很有可能会有数百个点).

Besides that, I would also like to display the centre of each cluster since this will help me see how my cluster building algorithm performs. To do this at the moment, I am writing some text on the graph through the use of the XPointerAnnotation class. The problem with this is that I think that having text on top of points can lead to a messy plot (considering that it is highly likely that there will be hundreds of points).

我想到了从中心点到群集的每个成员向外绘制的线.我面临的问题是，我似乎找不到合适的方法来做到这一点.

I thought of drawing lines going outwards, from the centre point to each of the members of its cluster. The problem I am facing is that I can't quite seem to find the correct method or methods which does that.

我设法找到了源 > XYLineAndShapeRenderer ，并尝试将其用作指导，但是在绘图上我仍然没有绘制自定义线.我试图覆盖drawPrimaryLine，drawPrimaryLineAsPath和drawSecondaryPass方法，但无济于事.

I have managed to find the source of XYLineAndShapeRenderer and have tried to use it as a guide, but I still get no custom lines drawn on the plot. I have tried to override the drawPrimaryLine, drawPrimaryLineAsPath and drawSecondaryPass methods, but to no avail.

我用来渲染线条的代码如下:

The code I am using to render the lines is as follows:

int x1 = (int) dataset.getXValue(series, 0);
int y1 = (int) dataset.getYValue(series, 0);

int x2 = (int) dataset.getXValue(series, item);
int y2 = (int) dataset.getYValue(series, item);

g2.drawLine(x1, y1, x2, y2);
System.out.println(String.format("Drawing %d  %d  %d  %d %s", x1, y1, x2, y2, g2.getColor()));

State s = (State) state;
if (item == s.getLastItemIndex()) {
    // draw path
    drawFirstPassShape(g2, pass, series, item, s.seriesPath);
}

print语句打印正确的坐标和正确的颜色，因此似乎我正在添加的图形没有被渲染.我尝试在执行代码之前和之后都调用super，但也无济于事.

The print statement prints the right coordinates and the right colours, so it just seems that the graphics that I am adding is not being rendered. I have tried calling super, both before and after my code is executed but to no avail either.

任何方向将不胜感激. 谢谢.

Any directions would be appreciated. Thanks.

推荐答案

更仔细地查看所发布的代码，从dataset获得的 xy 值表示 data 坐标.在渲染这样的点之前，必须将其转换为相对于dataArea的 graphics 坐标.例如，

Looking more closely at the code posted, the xy value obtained from the dataset represents a point in data coordinates. Before such a point can be rendered, it must be transformed into graphics coordinates, relative to the dataArea. As an example, drawPrimaryLineAsPath() uses the corresponding axis method, valueToJava2D(), to convert a data value to a graphics coordinate.

double transX1 = domainAxis.valueToJava2D(x1, dataArea, xAxisLocation);
double transY1 = rangeAxis.valueToJava2D(y1, dataArea, yAxisLocation);

附录:drawPrimaryLineAsPath() 方法/XYLineAndShapeRenderer.html#line.887"rel =" nofollow> drawItem() 仅当drawSeriesLineAsPath为true时，例如setDrawSeriesLineAsPath(true).

Addendum: The drawPrimaryLineAsPath() method is invoked from drawItem() only when drawSeriesLineAsPath is true, e.g. setDrawSeriesLineAsPath(true).

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