Appendix A
PDPTool Installation and Quick Start Guide

 A.1 System requirements
 A.2 Installation
 A.3 Using PDPTool at a Stanford Cluster Computer
 A.4 Using the software
 A.5 Notes when using Matlab 7.3 r2006b on OSX

PDPTool is a neural network simulator for Matlab that implements the models described in Parallel distributed processing: Explorations in the microstructure of cognition (Rumelhart et al.1986McClelland et al.1986). This program is a teaching aid for courses in Parallel Distributed Processing.

This document describes how to install and run PDPTool on your computer. For instructions on using the software, see the PDPTool User’s Guide, Appendix C.

If you encounter difficulties with installation, send email to:

NOTE: The version of the software available here does not work on MATLAB versions R2014a or later (see immediately below for details).

A.1 System requirements

A.2 Installation

Source files for PDPTool are located at

Install PDPTool using the following steps.

  1. Download the archive file “” to your desktop.
  2. Extract the archived files into a new folder called “pdptool”.
  3. Start Matlab.
  4. In Matlab, set your path variable to point to PDPTool using the following steps.
    1. From the File menu, select Set path. A dialog box opens.
    2. Click the Add with subfolders button. A directory browser window opens.
    3. Locate the folder called pdptool. Select it and click OK.
    4. Click the Save button on the set path dialog box to save the path for future sessions.
    5. Click the Close button.
  5. Set your command history preferences using the following steps.
    1. From the File menu, select Preferences. A dialog box opens.
    2. Select Command History from the list of options on the left. This displays the current command history settings.
    3. In the Saving section of the history settings, select Save after [n] commands, where [n] is a numerical field.
    4. Change [n] to 1.
    5. Click OK.
  6. At the Matlab command prompt, type “pdp” to start the program.

A.3 Using PDPTool at a Stanford Cluster Computer

If you use PDPTool at a Stanford cluster computer, install the program and save your work to your AFS filespace, which includes the desktop.

You will be unable to save your Matlab settings. At the beginning of each session, repeat steps 4 and 5 of Installation to set the correct path variable and command history preferences.

In the Set Path dialog box, do not click the Save button. When you click the Close button, a dialog box appears to ask if you would like to save the path. Click No.

A.4 Using the software

To start working with the exercises, change your working directory to the subdirectory of the program you wish to run. For the first exercise, move to the iac subdirectory of your pdptool directory.

Instructions on using PDPTool for the first exercise 2.1 are available in the Interactive Activation and Competition chapter. Also consult the PDPTool User’s Guide, Appendix C, for overall documentation.

A.5 Notes when using Matlab 7.3 r2006b on OSX

The graphical interface of PDPTool for this version of Matlab is imperfect. To set the value of the external input to a unit, right-click just outside the units square graphic instead of inside it.