RegressionGraph.java

package rainbownlp.analyzer.evaluation.regression;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.Stroke;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import javax.swing.*;

@SuppressWarnings("serial")
public class RegressionGraph extends JPanel {
	   private static final int MAX_SCORE = 20;
	   private static final int PREF_W = 800;
	   private static final int PREF_H = 650;
	   private static final int BORDER_GAP = 30;
	   private static final Color GRAPH_COLOR = Color.green;
	   private static final Color GRAPH_POINT_COLOR = new Color(150, 50, 50, 180);
	   private static final Stroke GRAPH_STROKE = new BasicStroke(3f);
	   private static final int GRAPH_POINT_WIDTH = 12;
	   private static final int Y_HATCH_CNT = 10;
	   List<Double> xValues;
	   List<Double> yValues;
	

	   public RegressionGraph(List<Double> xs, List<Double> ys) throws Exception {
		   if(xs.size()!=ys.size())
			   throw(new Exception("X and Y values must have same size"));
			xValues = xs;
			yValues = ys;
		}

	@Override
	   protected void paintComponent(Graphics g) {
	      super.paintComponent(g);
	      Graphics2D g2 = (Graphics2D)g; 
	      g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

	      double xScale = ((double) getWidth() - 2 * BORDER_GAP) / (xValues.size() - 1);
	      double yScale = ((double) getHeight() - 2 * BORDER_GAP) / (yValues.size() - 1);

	      List<Point> graphPoints = new ArrayList<Point>();
	      for (int i = 0; i < xValues.size(); i++) {
	         int x1 = (int) (xValues.get(i) * xScale + BORDER_GAP);
	         int y1 = (int) (yValues.get(i) * yScale + BORDER_GAP);
//	         int y1 = (int) ((MAX_SCORE - scores.get(i)) * yScale + BORDER_GAP);
	         graphPoints.add(new Point(x1, y1));
	      }

	      // create x and y axes 
	      g2.drawLine(BORDER_GAP, getHeight() - BORDER_GAP, BORDER_GAP, BORDER_GAP);
	      g2.drawLine(BORDER_GAP, getHeight() - BORDER_GAP, getWidth() - BORDER_GAP, getHeight() - BORDER_GAP);

//	      // create hatch marks for y axis. 
//	      for (int i = 0; i < Y_HATCH_CNT; i++) {
//	         int x0 = BORDER_GAP;
//	         int x1 = GRAPH_POINT_WIDTH + BORDER_GAP;
//	         int y0 = getHeight() - (((i + 1) * (getHeight() - BORDER_GAP * 2)) / Y_HATCH_CNT + BORDER_GAP);
//	         int y1 = y0;
//	         g2.drawLine(x0, y0, x1, y1);
//	      }
//
//	      // and for x axis
//	      for (int i = 0; i < scores.size() - 1; i++) {
//	         int x0 = (i + 1) * (getWidth() - BORDER_GAP * 2) / (scores.size() - 1) + BORDER_GAP;
//	         int x1 = x0;
//	         int y0 = getHeight() - BORDER_GAP;
//	         int y1 = y0 - GRAPH_POINT_WIDTH;
//	         g2.drawLine(x0, y0, x1, y1);
//	      }

	      Stroke oldStroke = g2.getStroke();
	      g2.setColor(GRAPH_COLOR);
	      g2.setStroke(GRAPH_STROKE);
	      for (int i = 0; i < graphPoints.size() - 1; i++) {
	         int x1 = graphPoints.get(i).x;
	         int y1 = graphPoints.get(i).y;
	         int x2 = graphPoints.get(i + 1).x;
	         int y2 = graphPoints.get(i + 1).y;
	         g2.drawLine(x1, y1, x2, y2);         
	      }

	      g2.setStroke(oldStroke);      
	      g2.setColor(GRAPH_POINT_COLOR);
	      for (int i = 0; i < graphPoints.size(); i++) {
	         int x = graphPoints.get(i).x - GRAPH_POINT_WIDTH / 2;
	         int y = graphPoints.get(i).y - GRAPH_POINT_WIDTH / 2;;
	         int ovalW = GRAPH_POINT_WIDTH;
	         int ovalH = GRAPH_POINT_WIDTH;
	         g2.fillOval(x, y, ovalW, ovalH);
	      }
	   }

	   @Override
	   public Dimension getPreferredSize() {
	      return new Dimension(PREF_W, PREF_H);
	   }

	   public static void createAndShowGui(List<Double> Xs, List<Double> Ys) throws Exception {
//	      List<Integer> scores = new ArrayList<Integer>();
//	      Random random = new Random();
//	      int maxDataPoints = 16;
//	      int maxScore = 20;
//	      for (int i = 0; i < maxDataPoints ; i++) {
//	         scores.add(random.nextInt(maxScore));
//	      }
	      RegressionGraph mainPanel = new RegressionGraph(Xs, Ys);

	      JFrame frame = new JFrame("DrawGraph");
	      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	      frame.getContentPane().add(mainPanel);
	      frame.pack();
	      frame.setLocationByPlatform(true);
	      frame.setVisible(true);
	   }

	   public static void main(String[] args) {
	      SwingUtilities.invokeLater(new Runnable() {
	         public void run() {
//	            createAndShowGui();
	         }
	      });
	   }
	
}