Java applets for power and sample size. Piface is intended to be useful in planning statistical studies. It is not intended to be used for analysis of data that have already been collected.
Each selection provides a graphical interface for studying the power of one or more tests. They include sliders (convertible to number-entry fields) for varying parameters, and a simple provision for graphing one variable against another. Each dialog window also offers a Help menu.
The options menu varies depending on the application, but most will provide at least the "Graphics" option. If this is selected, you will get a client dialog that "plays" the user interface for specified parameter values and graphs the results.
Please Note: This program require a web browser capable of running Java applets. The file piface.jar may be downloaded so that you can run these applications locally.
If you have JDK or JRE version 1.2 or later, then you can probably run the application just by double-clicking on piface.jar. Otherwise, you may run it from the command line in a terminal or DOS window, using a command like: java -jar piface.jar
This will bring up a selector list similar to the one in this web page. A particular dialog can also be run directly from the command line, if you know its name (can be discovered by browsing piface.jar with a zip file utility such as WinZip). For example, the two-sample t-test dialog may be run using
java -cp piface.jar rvl.piface.apps.TwoTGUI
The license of this software is Freeware, you can free download and free use this graphing software.