JFreeChart在不同区域的不同颜色为同一dataSeries

问题描述

在 JFreeChart 我试图根据 y 值为XY线图/曲线的不同区域着色。我正在覆盖 XYLineAndShapeRenderer 的 getItemPaint（int row，int col），但我不知道如何它处理 x 之间的线条着色，因为它只在上获得 itemPaint x （整数值）。

In JFreeChart I'm trying to color different regions of an XY line chart/curve based on y value. I'm overriding the XYLineAndShapeRenderer's getItemPaint(int row, int col), however I'm not sure how it handles the coloring of the line between the xs since it's only getting itemPaint on the x (integer values).

final XYLineAndShapeRenderer renderer = new XYLineAndShapeRenderer() {
    @Override

    @Override
    public Paint getItemPaint(int row, int col) {
        System.out.println(col+","+dataset.getY(row, col));
        double y=dataset.getYValue(row, col);
        if(y<=3)return ColorUtil.hex2Rgb("#7DD2F7");
        if(y<=4)return ColorUtil.hex2Rgb("#9BCB3B");
        if(y<=5)return ColorUtil.hex2Rgb("#FFF100");
        if(y<=6)return ColorUtil.hex2Rgb("#FAA419");
        if(y<=10)return ColorUtil.hex2Rgb("#ED1B24");

        //getPlot().getDataset(col).
        return super.getItemPaint(row,col);
    }
}

推荐答案

它看起来像行之间的着色处理是在 drawFirstPassShape

It looks like the handling of the colouring between lines is implemented in drawFirstPassShape

中实现的。线条颜色似乎是基于前一点

The line colour appears to be based on the preceding point

对 XYLineAndShapeRenderer 的此修改使用渐变填充来混合线条颜色。

This modification to your XYLineAndShapeRenderer uses a gradient fill to blend the line colour.

XYLineAndShapeRenderer renderer = new XYLineAndShapeRenderer(){
        @Override
        public Paint getItemPaint(int row, int col) {
            Paint cpaint = getItemColor(row, col);
            if (cpaint == null) {
                cpaint = super.getItemPaint(row, col);
            }
            return cpaint;
        }

    public Color getItemColor(int row, int col) {
        System.out.println(col + "," + dataset.getY(row, col));
        double y = dataset.getYValue(row, col);
        if(y<=3) return Color.black;
        if(y<=4) return Color.green;;
        if(y<=5) return Color.red;;
        if(y<=6) return Color.yellow;;
        if(y<=10) return Color.orange;;
        return null;
    }

    @Override
    protected void drawFirstPassShape(Graphics2D g2, int pass, int series,
        int item, Shape shape) {
        g2.setStroke(getItemStroke(series, item));
        Color c1 = getItemColor(series, item);
        Color c2 = getItemColor(series, item - 1);
        GradientPaint linePaint = new GradientPaint(0, 0, c1, 0, 300, c2);
        g2.setPaint(linePaint);
        g2.draw(shape);
    }
};

我已删除 ColorUtil.hex2Rgb 因为我没有访问该类/方法。您可能需要修改 GradientPaint 以考虑点之间的距离/渐变。

I've removed ColorUtil.hex2Rgb as I don't have access to that class/method. You may want to modify GradientPaint to take account of the distance/gradient between points.

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