How To create regression lines (standard deviation channel)

[sonali]

I am using jfreechart in my application from one month but i can not found how to draw linear regression channels on any time series jfreechart. we can draw xyline annotation but here many regression lines and its a series of regression lines so please help me how to draw it? chart displaying in upper image.

[John Matthews]

You may be able to use org.jfree.data.statistics.Regression in this context. There's a basic example here.

[sonali]

Thanks for the reply but sorry to say that according to this example when i will add more regression line data in trend then it will display jointed regression lines like line chart! i want to do same like image - a segmented regression lines.

[John Matthews]

When I add more regression line data…it will display jointed regression lines.

Right, Regression is just a convenient way to get the endpoints.

I want…segmented regression lines..

As it looks like you're using a HighLowRenderer, you may be able to adapt the approach shown in HighLowChartDemo2, which adds a second renderer to the plot, but I haven't tried it.

[paradoxoff]

1. Group your data into segments, one segment per regression line. We probably won't be able to help on that.
2. Calculate the regression line for the points in each section.
3. Get the first and last x value for each segment, and calculate the corresponding y value with the help of the regression line.
4. Use the first and last x and y values to construct a XYLineAnnotation. You may want to use the constructor that lest you specify a stroke (such as a new BasicStroke(3.0f)) and a Paint (such as Color.RED).
5. Add the XYLineAnnotation to the plot.

Note that this solution won't be dynamic,and will not automatically react to changes in the HighLowDataset.

[sonali]

1. Group your data into segments, one segment per regression line. ..
5. Add the XYLineAnnotation to the plot.
Note that this solution won't be dynamic,and will not automatically react to changes in the HighLowDataset.

i had created a functionality of edit chart (user can drag and drop mouse and draw line on chart) where i am using xyline annotation and to remove it another option is also for clear all annotation . you had give me a solution that will work but right now that's not the logic which will help me. Thanks.

[sonali]

I got the solution , if someone have requirement as my question here is demo code:

Code: Select all

import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Paint;
import java.util.Random;

import javax.swing.JFrame;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYItemRenderer;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
import org.jfree.data.xy.XYDataset;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;

public class RegressionTest {

	private static final int N = 16;
	private static final Random R = new Random();

	private static XYDataset createDataset() {
		XYSeries series = new XYSeries("Data");
		for (int i = 0; i < N; i++) {
			series.add(i, R.nextGaussian() + i);
		}
		XYSeriesCollection xyData = new XYSeriesCollection(series);
		/*//count regression data------------------ as requirement
        double[] coefficients = Regression.getOLSRegression(xyData, 0);
        double b = coefficients[0]; // intercept
        double m = coefficients[1]; // slope

        double x = series.getDataItem(0).getXValue();
        System.out.println("x:"+x+"m:"+m+"b:"+b+"ans:"+ m * x + b);
        trend.add(x, m * x + b);
        x = series.getDataItem(series.getItemCount() - 1).getXValue();
        System.out.println("x:"+x+"m:"+m+"b:"+b+"ans:"+ m * x + b);
        trend.add(x, m * x + b);

		 */
		XYSeries trend = new XYSeries("Trend");
		//add here regressiondata
		//here dummydata added
		trend.add(1, 2);//1 st regression line startpoint
		trend.add(3,4);//1 st regression line endpoint
		
		trend.add(5,6);//2  regression line startpoint
		trend.add(7,9);//2 regression line endpoint
		
		trend.add(7.5,8.5);//3  regression line startpoint
		trend.add(10,7);//3 regression line endpoint
		
		trend.add(9,8);//4  regression line startpoint
		trend.add(12,12);//4 regression line endpoint
		
		xyData.addSeries(trend);

		return xyData;
	}

	private static JFreeChart createChart(final XYDataset dataset) {
		JFreeChart chart = ChartFactory.createXYLineChart("Test", "X", "Y",
				dataset, PlotOrientation.VERTICAL, true, false, false);
		return chart;
	}

	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			@Override
			public void run() {
				JFrame f = new JFrame();
				f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
				XYDataset dataset = createDataset();
				JFreeChart chart = createChart(dataset);
				XYPlot plot=chart.getXYPlot();
				XYItemRenderer renderer = new CustomLineRenderertest(true,false);
				plot.setRenderer(renderer);
				ChartPanel chartPanel = new ChartPanel(chart) {
					
					private static final long serialVersionUID = 1L;

					@Override
					public Dimension getPreferredSize() {
						return new Dimension(640, 480);
					}
				};
				f.add(chartPanel);
				f.pack();
				f.setLocationRelativeTo(null);
				f.setVisible(true);
			}
		});
	}
}

class CustomLineRenderertest extends XYLineAndShapeRenderer {
	/**
	 * for add study line chart red green
	 */
	private static final long serialVersionUID = 1L;

	public CustomLineRenderertest(boolean lines, boolean shapes){
		super(lines, shapes);
	}

	@Override
	public Paint getItemPaint(int row, int column) {
		if(row>0){
			if(column%2==0){
				return new Color(0, 0,0, 0);
			}else{
				return Color.red;
			}

		}
		return Color.blue;
	}
}

This is not perfect solution but my work done! you have to modifies as your requirement if you are using time series jfreechart.

[John Matthews]

As an aside, your renderer's colors don't match the legend. One mitigation strategy is to let your implementation of getItemPaint() obtain the parent Paint and return it as needed. For example,

Code: Select all

private static final Paint TRANSPARENT_BLACK = new Color(0, 0, 0, 0);
…
@Override
public Paint getItemPaint(int row, int column) {
	Paint p = super.getItemPaint(row, column);
	if (row > 0) {
		if (column % 2 == 0) {
			return TRANSPARENT_BLACK;
		} else {
			return p;
		}
	}
	return p;
}

[sonali]

As an aside, your renderer's colors don't match the...

Its work Perfect! Thank you.