Object Library > Applets
An applet is a small, self-contained program that runs in a web page. Applets are intended to illustrate concepts and techniques in an interactive, dynamic way. A teacher or student can download an applet, drop it in a web page, and then add other elements of her own choice (such as expository text, data sets, and graphics). Many of the applets in the library contain essentially no explicit mathematical analysis, and thus can be used by students and teachers at various levels. These applets are intended to be small "micro worlds" where students can run virtual versions of random experiments and play virtual versions of statistical games. This page includes a list of all applets in the library
If you want to use all of the applets in the library, click on the link below to download a jar file (Java Archive File) that contains all class and resource files for the applets:
To add an applet to your web page, insert the following in the html file, at the point where you want the applet to appear:
<applet code="edu.uah.math.experiments.AppletName.class"
archive="PSOL.jar" width="600" height="400"></applet>
where AppletName is the name of the particular applet (for example, BuffonNeedleExperiment). The jar file and the html file must be in the same folder. This width and height dimensions are simply suggestions and can be varied. Generally, components such as graphs and tables expand and contract proportionally, while components such as buttons, scrollbars, dice, and coins are fixed in size.
This method is recommended if you want to use the applets locally, either on individual computers or on an intranet. On the Internet, the time required to load a page with an applet may be quite long, particularly for the first applet, because of the size of the jar file.
If you want to download a few specific applets, visit the pages for the applets that you want (links to these pages are in the list below). The page for each applet includes
This is the best approach in terms of perfomance, since each jar file contains just the files necessary for the particular applet.
The applets in the library require the Java 2 Runtime Environment. Click on the link to download and install the appropriate plug-in for your broswer.
The expository text that describes some of the applets uses MathML, the Mathematics Markup Language, for notationally correct and portable mathematical expressions. Thus, to view the mathematical notation properly, your browser must support MathML (although MathML support is not necessary to run or download the applets). At the present time, the best configuration is Microsoft Windows with Internet Explorer 6.0 or later, with the MathPlayer plug-in. Click on the links to upgrade your browser and insall the plug-in
The other option is Netscape Navigator 7.0 or later, with MathML enabled and the appropriate fonts installed. However, the display of the mathematical expressions encoded in MathML is not as good as the first option above. Click on the link to upgrade your browser.
A standard graphical interface is used, with command buttons, scroll bars and list boxes, and is very similar for each applet. There is no programming or command language of any form, so students should be able to run the applets with little or no instructions.
The applet output is displayed numerically and graphically in a set of coordinated tables and graphs. A consistent color-coding is used. Graphical objects that depend only on the distributions or parameters are shown in blue, while graphical objects that depend on data (either simulation or student generated) are shown in red.
The numerical results are displayed in tables. On most platforms, the output of a table can be selected and then copied to the clipboard in standard tab-separated format. The copied data can then be imported into a spreadsheet, statistical, or word processing program for further analysis or use in a student report.
Applets that are simulations of random processes have the following basic buttons on the top toolbar:
The update frequency is selected from the first list box on the top toolbar. This number determines how often graphical and numerical displays are updated in run mode. In most applets, you can select an update frequency of 1, 10, 100, or 1000. In some applets, other update rules are provided. An update occurs automatically if the simulation is stopped by clicking the stop button.
The stop frequency is selected from the second list box on the top toolbar. The stop frequency is the number of runs before the simulation stops in run mode. In most applets you can select a stop frequency of 10, 100, 1000, or 10000. In some applets, other stop rules are provided.
The student can easily vary the parameters, select distributions, and choose among appropriate modeling assumptions using list boxes, scroll bars, and pop-up dialog boxes. These controls appear on toolbars at the top of the applet window. The toolbars can be "undocked" into separate windows that can be moved to a convenient place on the desktop. In particular, if some of the controls are not visible, undocking the toolbar will reveal these controls.