a pedagogical implementation of the Simplex method

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pplex is an application that can interpret linear programs (LP) and show how the LP dictionary evolves throughout the execution of the simplex method.

pplex is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

pplex uses Apache Commons Math library for handling matrices. It is released under the Apache License, Version 2.0. See lib/LICENSE.TXT for more information.

pplex supports visualization

Try the pplex applet!


Documentation on how to use pplex can be found here.

Reporting Bugs

GitHub's issue tracker is used for tracking bugs of pplex. Before submitting a bug you should make sure that you are running the latest version of pplex, and that the bug has not already been submitted to the tracker on GitHub.

Installing pplex

If you want to try pplex before installing it, you can try it as an applet by visiting http://pplex.ii.uib.no. It has most of the functionality of pplex (but you cannot read your own files.)

Running pplex requires Java Runtime Environment installed on your computer.

  1. Download the newest version of pplex from one of the links above.
  2. Extract the archive.
  3. Double-click on pplex.jar.
  4. (Getting started) Type read input/vdb2.8.lps in pplex' console.

Running pplex

pplex starts in visual mode by default. This is only relevant for linear programs with two variables. pplex can easily be run without a graphical interface in a terminal window by passing the '-nogui' argument like this: java -jar pplex.jar -nogui

Compiling pplex

Compiling pplex requires:

  • Java Development Kit
  • Apache Ant

To compile pplex you first need to download the source code of pplex. This can be done from the website or by cloning the repository.

To clone the repository you need git installed on your system. Cloning the repository is done by typing the following in a terminal: git clone git@github.com:andern/pplex.git

To only compile the sources of pplex, run ant compile in the pplex directory.

To compile the sources of pplex and build a runnable jar, run ant jar or simply ant


pplex can be compiled as an applet by running ant applet in the pplex directory.

See applet.html in the pplex directory for an example on how to deploy the applet on your own website.