Lens Icon
the light, efficient network simulator

version 2.64-cnbc.1

User's Guide

Installing Lens
Running Lens
Example Networks
Tcl/Tk Basics
Commands and the Shell

Graphical Displays

Main Window
Object Viewer
Unit Viewer
Link Viewer

File Formats and Usage

General File Usage
Script Files
Example Files
Activation Output Files
Weight Files

Special Topics

Time and Events
Group Types: Basic, Input, Output, Cost
Building and Initializing Networks
Training Standard Networks
Simple Recurrent Networks
Fully Recurrent and Continuous Networks
Deterministic Boltzmann Machines
Parallel Training
Doug's Rules of Thumb

Programmer's Guide

Using Lens as a Library
The Code
The Structures
General Coding Issues
Flow of Control

How to Create...

Shell Commands
Fields in an Object or Extension
Network Types
Group Types
Weight Update Algorithms
Example Loading Commands
Group Connection Procedures
Graphical Displays
Hebbian or Other Networks


Hey, I Found a Bug!
Frequently Asked Questions
Common Problems
Version Notes
CNBC Enhancements
CNBC published models

Command Reference
Tcl/Tk Reference
Offline Manual

Source Code

Lens was originally created by Douglas Rohde

The current version was maintained for several years at Carnegie Mellon at the Center for the Neural Basis of Cognition, and is now being hosted by the parallel distributed processing lab at Stanford. Currently, the pdplab is not continuing to maintain lens, and the installation instructions as well as the code may require updating.

We are happy to share this resource given these caveats. If you attempt to use it, and you run into difficulties that you cannot overcome, feel free to contact pdplab support ; we may be able to direct you to someone who can help.

web counter
free web hit counters gallery