JavaScript Examples

Superposition Interface

Superposition may be embedded within your own web page with the following HTML tags:

<applet code="Regression.class" width=600 height=400>
<PARAM NAME="dt" VALUE=0.1>
<PARAM NAME="FPS" VALUE=20>
<PARAM NAME="numPoints" VALUE=200>
<PARAM NAME="numGraphs" VALUE=2>
<PARAM NAME="pixPerX" VALUE=10>
<PARAM NAME="pixPerY" VALUE=10>
<PARAM NAME="gridX" VALUE=1>
<PARAM NAME="gridY" VALUE=1>
<PARAM NAME="showControls" VALUE=true>
<PARAM NAME="func1" VALUE="sin(x-2*t)" >
<PARAM NAME="func2" VALUE="cos(x+2*t)" >
<PARAM NAME="helpFile" VALUE="superpositionHelp.html" >
</APPLET>

where dt is the time step and FPS is the frames per second. These parameters may need to be adjusted to produce smooth animation on less powerful computers. PixPerX and pixPerY specifies the scale while gridX and gridY specity the grid spacing. If gridX (gridY) is set to zero the X (Y) grid will not be drawn. The showControls parameter is designed to reduce the screen size of the Applet. This parameter allows the HTML programmer to hide the buttons displayed at the bottom of the applet. JavaScript can be used to change the function being animated.

Superposition may be scripted using the following Java method calls:

• forward()
• setCaption(String caption)
• setCaption(int n, String caption)
• setFunc1(String s)
• setFunc2(String s)
• stepBack()
• stepForward()
• start()
• stop()
• setRGB(int r, int g, int b)
• setRGB(int n, int r, int g, int b)
• reset()
• reset(double time)
• reverse()

Use the codebase tag if the Superposition.class file is in a different directory than the HTML page that uses the applet. (See source for this page.) All Java packages used by Superposition, such as the graph package which contains the parser class, must be in subdirectories below the Superposition.class file.

Superposition.zip may be downloaded for noncommercial use by students and faculty at accredited not-for-profit educational institutions. The zip file being distribted is uncompresssed and can be used with the new Netscape Archive tag. (See source code for this page.) The archive tag allows Netscape to download all the necessary files with a single HTTP request to the server. It is much faster than the standard download method which requires a HTTP request for each file. You should, however, keep copies of the uncompressed class files in the class directory so that browers that do not support the archive tag will be able to run the applet.

Superposition was written using Java 1.01. It will be rewritten as a Java "Bean"using the newer (and better) Java event model avaliable in Java 1.1. Consequently, this applet is date stamped for July 15, 1997.