FileDocCategorySizeDatePackage
Grapher.javaAPI DocExample3697Thu May 27 22:01:30 BST 2004None

Grapher

public class Grapher extends JPanel
Simple Graphing program.
author
Ian F. Darwin, http://www.darwinsys.com/
version
$Id: Grapher.java,v 1.15 2004/05/28 02:01:30 ian Exp $

Fields Summary
public static final double
BORDERFACTOR
Multiplier for range to allow room for a border
protected List
data
The list of Point points.
protected double
minx
The minimum and maximum X values
protected double
maxx
protected double
miny
The minimum and maximum Y values
protected double
maxy
protected double
xrange
The range of X and Y values
protected double
yrange
Constructors Summary
public Grapher()


	  
		data = new ArrayList();
		figure();
Methods Summary
private voidfigure()
Compute new data when list changes

		// find min & max
        for (int i=0 ; i < data.size(); i++) {
			Point2D d = (Point2D)data.get(i);
			if (d.getX() < minx) minx = d.getX();
			if (d.getX() > maxx) maxx = d.getX();
			if (d.getY() < miny) miny = d.getY();
			if (d.getY() > maxy) maxy = d.getY();
        }

		// Compute ranges
		xrange = (maxx - minx) * BORDERFACTOR;
		yrange = (maxy - miny) * BORDERFACTOR;
		Debug.println("range", "minx,x,r = " + minx +' "+ maxx +' "+ xrange);
		Debug.println("range", "miny,y,r = " + miny +' "+ maxy +' "+ yrange);
public java.awt.DimensiongetPreferredSize()

		return new Dimension(150, 150);
public static voidmain(java.lang.String[] args)

		final JFrame f = new JFrame("Grapher");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		Grapher grapher = new Grapher();
		f.setContentPane(grapher);
		f.setLocation(100, 100);
		f.pack();
		List data = null;
		if (args.length == 0)
			data = GraphReader.read("Grapher.dat");
		else {
			String fileName = args[0];
			if ("-".equals(fileName)) {
				data = GraphReader.read(new InputStreamReader(System.in), "System.in");
			} else {
				data = GraphReader.read(fileName);
			}
		}
		grapher.setListData(data);
		f.setVisible(true);
public voidpaintComponent(java.awt.Graphics g)
Called when the window needs painting. Computes X and Y range, scales.

		super.paintComponent(g);
		Dimension s = getSize();
		if (data.size() < 2) {
			g.drawString("Insufficient data: " + data.size(), 10, 40);
			return;
		}

		// Compute scale factors
		double xfact =  s.width  / xrange;
		double yfact =  s.height / yrange;

		// Scale and plot the data
        for (int i=0 ; i < data.size(); i++) {
			Point2D d = (Point2D)data.get(i);
			double x = (d.getX() - minx) * xfact;
			double y = (d.getY() - miny) * yfact;
			Debug.println("point", "AT " + i + " " + d + "; " +
				"x = " + x + "; y = " + y);
			// Draw a 5-pixel rectangle centered, so -2 both x and y.
			// AWT numbers Y from 0 down, so invert:
			g.drawRect(((int)x)-2, s.height-2-(int)y, 5, 5);
		}
public voidsetListData(java.util.List newData)
Set the list from an existing List, as from GraphReader.read()

		data = newData;
		figure();
public voidsetListDataFromYStrings(java.util.List newData)
Set the list data from a list of Strings, where the x coordinate is incremented automatically, and the y coordinate is made from the String in the list.

		data.clear();
		for (int i=0; i < newData.size(); i++) {
			Point2D p = new Point2D.Double();
			p.setLocation(i, java.lang.Double.parseDouble((String)newData.get(i)));
			data.add(p);
		}
		figure();