BinomConf -- Binomial Confidence Intervals


BinomConf is a simple calculator of binomial confidence intervals. Given a number of trials, a number of successes (or failures) observed in those trials, and a confidence limit, it will calculate the confidence interval around the observation. For example, given 500 trials, if you observe some event 5 times, the 95% confidence interval for the frequency of those events runs from 0.33% to 2.32%. The 90% confidence interval would roun from 0.4% to 2.09%. And so on.

The program was originally written to handle very high numbers of trials, in the multiple thousands. Statistics programs back then could not seem to handle such a large number of trials correctly.

In addition to its main purpose as a calculator, the BinomConf project is an ongoing example and reminder of how to do certain things. For example:

  • Save and restore configuration information
  • Use a pluggable look and feel
  • Set up program help
  • Do validation of user input
  • Unit test at the UI level

Building, Testing and Running

BinomConf was originally written back before IDEs were very good. As a result, the build file was written for Ant. Since that time, it has been mostly converted to a NetBeans IDE project.

However, the transition is incomplete. You can use NetBeans to build and run the program, but you can't run unit tests successfully. For that, you need to run the Ant script from the command line.

c:\ant test

To run the program, run the binomconf.bat file from a Windows command prompt.

Help is available by clicking the "Help" button in the main program.

The program source is available from the zip file. Unzip it into this directory and a new directory, "src" should be created with additional subdirectories for the main program and a set of tests.

An Ant script is provided to rebuild the program or its documentation.

The contents of the "lib" directory are third party jars used to build the program interface or to assist in testing the program.