Scatter Plot
/*************************************************************************
* *
* This source code file, and compiled classes derived from it, can *
* be used and distributed without restriction, including for commercial *
* use. (Attribution is not required but is appreciated.) *
* *
* David J. Eck *
* Department of Mathematics and Computer Science *
* Hobart and William Smith Colleges *
* Geneva, New York 14456, USA *
* Email: eck@hws.edu WWW: http://math.hws.edu/eck/ *
* *
*************************************************************************/
import edu.hws.jcm.awt.*;
import edu.hws.jcm.data.*;
import edu.hws.jcm.draw.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
import java.util.*;
import java.applet.Applet;
/**
* A ScatterPlotApplet shows a scatter plot of data from a DataTableInput.
* The user can enter the data in a two-column table that is shown in
* the applet. It is also possible to configure the applet with a menu
* of file names. These files, which must be in the same directory as
* the Web page on which the applet appears, will appear in a menu.
* A file can contain data for the table, with two numbers per line.
* When the user loads the file, the data replaces the data in the table.
*/
public class ScatterPlotApplet extends Applet implements ActionListener {
private Frame frame; // If non-null, a separate window.
private String frameTitle; // Title for the separate window.
private Button launchButton; // If non-null, then clicking this buttons opens a separate window.
private String launchButtonName; // Name for the launch button.
private DataTableInput table; // The table for input of data.
private ScatterPlot scatterPlot; // The scatter plot of the data.
private DisplayCanvas canvas; // The DisplayCanvas on which the plot is drawn.
private Button loadFileButton; // When clicked, a data file is loaded.
private Choice fileMenu; // Pop-up menu containing names of functions.
private String[] fileNames; // Names of data files associated with menu entries.
private Controller mainController; // Controller from the main JCMPanel.
/**
* The init() method is called by the system to set up the applet.
* If the applet does not appear as a button, then init() creates the main panel of the applet
* and calls setUpMainPanel to set it up.
*/
public void init() {
frameTitle = getParameter("FrameTitle"); // Get title to be used for separate window, if any.
if (frameTitle == null) {
frameTitle = "Scatter Plots";
int pos = frameTitle.lastIndexOf('.');
if (pos > -1)
frameTitle = frameTitle.substring(pos+1);
}
setLayout(new BorderLayout());
int height = getSize().height;
launchButtonName = getParameter("LaunchButtonName");
if ( (height > 0 && height <= 50) || launchButtonName != null) {
// Use a separater window and only show a button in the applet.
if (launchButtonName == null)
launchButtonName = "Launch " + frameTitle;
launchButton = new Button(launchButtonName);
add(launchButton, BorderLayout.CENTER);
launchButton.addActionListener(this);
}
else {
// Show the main panel in the applet, not in a separate window.
add(makeMainPanel(), BorderLayout.CENTER);
}
}
/*
* Create the main panel of the applet.
*/
public Panel makeMainPanel() {
// Make the main panel
JCMPanel panel = new JCMPanel(2);
mainController = panel.getController();
panel.setBackground(new Color(0,0,180));
panel.setInsetGap(2);
setLayout(new BorderLayout());
// Make a DataInputTable with two columns
table = new DataTableInput(null, 2);
table.setColumnName(0, getParameter("ColumnName1", "X"));
table.setColumnName(1, getParameter("ColumnName2", "Y"));
table.setThrowErrors(true);
if ( "yes".equalsIgnoreCase(getParameter("ShowColumnTitles","yes")))
table.setShowColumnTitles(true);
if ( "yes".equalsIgnoreCase(getParameter("ShowRowNumbers","yes")))
table.setShowRowNumbers(true);
// Make input boxes for getting expressions that can include
// the variables associated with the table. Initially, the
// expressions are just the column names.
Parser parser = new Parser();
table.addVariablesToParser(parser);
ExpressionInput input1 = new ExpressionInput(table.getColumnName(0),parser);
input1.setOnUserAction(mainController);
ExpressionInput input2 = new ExpressionInput(table.getColumnName(1),parser);
input2.setOnUserAction(mainController);
// Make a scatter plot that graphs the first expressiong vs. the second expression.
scatterPlot = new ScatterPlot(table, input1.getExpression(), input2.getExpression());
if ( ! "yes".equalsIgnoreCase(getParameter("ShowRegressionLine","yes")))
scatterPlot.setShowRegressionLine(false);
if ( ! "yes".equalsIgnoreCase(getParameter("MissingValueIsError","yes")))
scatterPlot.setMissingValueIsError(false);
// Create the display canvas where the scater plot will be shown.
canvas = new DisplayCanvas();
canvas.add(new Axes());
canvas.add(scatterPlot);
mainController.setErrorReporter(canvas);
// A compute button to recompute everything.
ComputeButton computeButton = new ComputeButton("Update Display");
computeButton.setOnUserAction(mainController);
computeButton.setBackground(Color.lightGray);
// A menu of files that can be loaded. If no filenames are provided as
// applet parameters, then menu is null.
Panel menu = makefileMenu();
// Lay out the components in the applet.
JCMPanel inputPanel = null;
Panel bottom = null; //might not be a JCMPanel
if ( "yes".equalsIgnoreCase(getParameter("UseExpressionInputs","yes"))) {
inputPanel = new JCMPanel(1,2);
inputPanel.setBackground(Color.lightGray);
JCMPanel leftInput = new JCMPanel();
leftInput.add(new Label(" Plot: "), BorderLayout.WEST);
leftInput.add(input1, BorderLayout.CENTER);
inputPanel.add(leftInput);
JCMPanel rightInput = new JCMPanel();
rightInput.add(new Label(" versus: "), BorderLayout.WEST);
rightInput.add(input2, BorderLayout.CENTER);
inputPanel.add(rightInput);
bottom = new JCMPanel(new BorderLayout(12,3));
bottom.add(inputPanel, BorderLayout.CENTER);
bottom.add(computeButton, BorderLayout.EAST);
}
if ( scatterPlot.getShowRegressionLine() && "yes".equalsIgnoreCase(getParameter("ShowStats","yes")) ) {
// Make a display label to show some statistics about the data.
DisplayLabel dl = new DisplayLabel(
"Slope = #; Intercept = #; Correlation = #",
new Value[] { scatterPlot.getValueObject(ScatterPlot.SLOPE),
scatterPlot.getValueObject(ScatterPlot.INTERCEPT),
scatterPlot.getValueObject(ScatterPlot.CORRELATION) }
);
dl.setAlignment(Label.CENTER);
dl.setBackground(Color.lightGray);
dl.setForeground(new Color(200,0,0));
dl.setFont(new Font("Serif",Font.PLAIN,14));
if (bottom != null)
bottom.add(dl, BorderLayout.SOUTH);
else {
bottom = new JCMPanel(new BorderLayout(12,3));
bottom.add(dl, BorderLayout.CENTER);
bottom.add(computeButton, BorderLayout.EAST);
}
}
if (bottom == null) {
if (menu != null)
menu.add(computeButton, BorderLayout.EAST);
else {
bottom = new Panel();
bottom.add(computeButton);
}
}
panel.add(canvas, BorderLayout.CENTER);
panel.add(table, BorderLayout.WEST);
if (bottom != null)
panel.add(bottom, BorderLayout.SOUTH);
if (menu != null)
panel.add(menu, BorderLayout.NORTH);
else {
String title = getParameter("PanelTitle");
if (title != null) {
Label pt = new Label(title, Label.CENTER);
pt.setBackground(Color.lightGray);
pt.setForeground(new Color(200,0,0));
pt.setFont(new Font("Serif",Font.PLAIN,14));
panel.add(pt, BorderLayout.NORTH);
}
}
return panel;
} // end makeMainPanel()
private Panel makefileMenu() {
// If the applet tag contains params named "File", "File1", "File2", ..., use
// their values to make a file menu. If the value of the param contains a ";",
// then the first part, up to the ";", goes into the menu and the second part
// is the name of the file. If there is no ";", then the entire value is
// shown in the menu and is also used as the name of the file. The actual
// files must be in the same directory as the Web page that contains the applet.
Vector names = new Vector();
fileMenu = new Choice();
String file = getParameter("File");
int ct = 1;
if (file == null) {
file = getParameter("File1");
ct = 2;
}
while (file != null) {
file = file.trim();
int pos = file.indexOf(";");
String menuEntry;
if (pos == -1)
menuEntry = file;
else {
menuEntry = file.substring(0,pos).trim();
file = file.substring(pos+1).trim();
}
names.addElement(file);
fileMenu.add(menuEntry);
file = getParameter("File" + ct);
ct++;
}
if (names.size() == 0) {
fileMenu = null;
return null;
}
else {
fileNames = new String[names.size()];
for (int i = 0; i < names.size(); i++)
fileNames[i] = (String)names.elementAt(i);
Panel p = new Panel();
p.setBackground(Color.lightGray);
p.setLayout(new BorderLayout(5,5));
p.add(fileMenu,BorderLayout.CENTER);
loadFileButton = new Button("Load Data File: ");
loadFileButton.addActionListener(this);
p.add(loadFileButton,BorderLayout.WEST);
fileMenu.setBackground(Color.white);
return p;
}
}
private void doLoadFile(String name) {
// Load the file from the same directory as the Web page and put the data
// from the file into the table. The file should contain two numbers on
// each line.
InputStream in;
try {
URL url = new URL(getDocumentBase(), name);
in = url.openStream();
}
catch (Exception e) {
canvas.setErrorMessage(null,"Unable to open file named \"" + name + "\": " + e);
return;
}
Reader inputReader = new InputStreamReader(in);
try {
table.readFromStream(inputReader);
inputReader.close();
}
catch (Exception e) {
canvas.setErrorMessage(null,"Unable to get data from file \"" + name + "\": " + e.getMessage());
return;
}
mainController.compute();
}
/**
* Respond when user clicks a button; not meant to be called directly.
* This opens and closes the separate window.
*/
synchronized public void actionPerformed(ActionEvent evt) {
Object source = evt.getSource();
if (loadFileButton != null && source == loadFileButton) {
doLoadFile( fileNames[fileMenu.getSelectedIndex()] );
}
else if (source == launchButton && launchButton != null) {
// Open or close separate frame.
launchButton.setEnabled(false);
if (frame == null) {
frame = new Frame(frameTitle);
frame.add(makeMainPanel());
frame.addWindowListener( new WindowAdapter() {
public void windowClosing(WindowEvent evt) {
frame.dispose();
}
public void windowClosed(WindowEvent evt) {
frameClosed();
}
} );
frame.pack();
frame.setLocation(50,50);
frame.show();
launchButton.setLabel("Close Window");
launchButton.setEnabled(true);
}
else {
frame.dispose();
}
}
}
synchronized private void frameClosed() {
// respond when separate window closes.
frame = null;
launchButton.setLabel(launchButtonName);
launchButton.setEnabled(true);
}
/**
* Return the applet parameter with a given param name, but if no
* such applet param exists, return a default value instead.
*/
protected String getParameter(String paramName, String defaultValue) {
String val = getParameter(paramName);
return (val == null)? defaultValue : val;
}
public static void main(String[] a){
javax.swing.JFrame f = new javax.swing.JFrame();
Applet app = new SimpleGraph();
app.init();
f.getContentPane().add (app);
f.pack();
f.setSize (new Dimension (500, 500));
f.setVisible(true);
}
} // end class ScatterPlotApplet
jcm1-source.zip( 532 k)Related examples in the same category
