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University of Plymouth | Centre for Theoret. and Comput. Neuroscience| Home   

Felix - a Simulation-tool for Neural Networks and Dynamic Systems

NOTE: It appears that the Felix graphical user interface is no longer compatible with newer Linux-versions. The old XView libraries do not cooperate well with new X11/Xorg version.

What do you find here?

This page provides the run-time libraries of Felix compiled for i386 architecturesrunning Linux. Also available are a couple of examples and development files in caseyou want to develop your own Felix programs.

What is "Felix"?

Felix is a development tool for neural network and dynamical systems simulations. It is C-based and provides a simple to use graphical interface as well as a core of routines needed in many applications. Routines required in special applications can easily be added. Felix is best suited for one and two-dimensional network models, but other topologies are possible as well.

Main philosophy of Felix is to consider a neural network or dynamical system as a set of variables, x, which obey a certain dynamics and a second set of parameters, p, which control the dynamics. Canonical examples are difference schemes, x(t+1) = f(x(t);p) or differential equations, dx/dt = f(x;p). The graphical interface then presents the variables in various possible views like graphs and raster plots over time, or images and functions per single time-step. Parameters are further displayed as a collection of switches and sliders, whereby it becomes possible to change parameters in a running simulation and immediately observe the induced changes in the system dynamics.

The examples

The following links open up pages whith screen-shots, downloadable executables, and in part also source code of various Felix example programs.

The examples all contain static binaries that should run on any Linux i386 box.

• A 1D coupled map lattice
• Integrate and Fire Neural Network
• A network of coupled chaotic Roessler oscillators
• Carandini-Ringach field model for orientation tuning
• 2D excitatory-inhibitory neural field model
• A simple model for the primary visual cortex

To run the dynamically linked examples on your machine you need a Linux-PC with Xview set up,as well as the Felix libraries provided below. You do not need theXview and Felix development kits.

What do you need to run the examples?

There are several answers to this question, because most of the examples provide statically and dynamically linked executables.

For the statically linked executables all you need is a Linux computer (i386 compatible). You should download the executables and the environment files from the respective example pages above. Note that both have the same name, like, e.g., "inf" or "v1sd": You need to place the environment files in a sub-directory "env" of the directory where you store the executables. The executables then load appropriate parameter settings from the environment files. This is not entirely necessary, the executables would run without the environment files, but it is convenient, because all you have to do after starting a program is pressing the run-button in the upcoming user interfaces to see something happen.

You start the statically linked programs from a shell. You can also do this by clicking on them, but in that case, they are very likely started in your home-directory such that the environment files are not found. They should start nonetheless, but not necessarily with useful parameters and windows already open.

If the statically linked executables don't start, it might be necessary to make them executable by setting the right permission from a browser or by using the Linux command "chmod" (chmod 700 progname should do it). If this is not the reason for the failure, try "ldd progname" (where progname is the programs name) to see whether some libraries are missing (only the Felix and xview libraries are statically linked in. X11-libs and other Linux standard libraries are not).

The dynamically linked Felix examples need the Felix run-time libraries. You also need the Open-Look and Xview runtime libraries, which might (or might not) be located in the following places on your system:

/usr/openwin/lib/libolgx.so.3.2.??
/usr/openwin/lib/libxview.s o.3.2.??

If your libs are older than version 3.2.4 it is recommended to replace them by newer ones. The libs come with many Linux distributions but they are not necessarily installed by default. If you don't have them on your computer or Linux-CDs, search for "xview-3.2p1" at google or your most favourite search engine on the web.

Felix programs need the Felix runtime libraries which you find HERE. (Unpack and extract; then follow instructions in README.txt.)

Alternatively (and easier) the Debian and RPM packages provided below contain both, the felix libs and development files. But they do no contain the xview libs.

What do you need to develop your own Felix programs?

If you want to use Felix for your own applications you need the runtimelibraries as described in the previous paragraph, and in addition the Xview-and the Felix-development kits.

The Xview development kit as the Xview runtime libraries comes with manylinux distributions but is not necessarily installed by default. If you havexview installed then there should be non-empty subdirectories xview,xview_private, olgx, olgx_private, and pixrect in /user/openwin/include orwhereever you have installed Xview. If you don't have Xview on yourComputer or Linux-CDs search for "xview-3.2p1 devel" at google.

The Felix development kit contains C-header files and scripts youneed to compile your own programs. Get the kit and installation instructionsHERE.(Unpack and extract, and follow instructions in README.devel.txt.)

ALternatively (and easier) the Debian and RPM packages provided below contain both, the felix libs and development files. But they do no contain the xview libs.

User Guide

The Felix user guide is HERE. Note that it is under development and that the parallel extensions and possibly other features mentioned in the text are not currently publicly available.

Historical remarks

Felix is old. The original program was written about 1990/91 in multiC, a version of C for the parallel computer Wavetracer which consisted of 4096 one-bit processors in a SIMD-architecture, freely configurable as a 1, 2 or 3-D array. The early Felix was meant to serve as a graphical interface for that machine. The Wavetracer was about 20 times faster than a standard Sun-Workstation 15 years ago. When standard workstations became quicker, and in particular quicker than the Wavetracer, I ported Felix to run under SunOs and Solaris, and later, when I discovered that even cheap laptops are faster than standard Sun-workstations I further ported it to Linux. Now, I am almost exclusively using it under Linux on desktop and laptop PCs.

Because Felix is old, it makes use of an outdated windows toolkit, called Xview. For a while that was quite standard for Sun X11 applications with the Open-Look look and feel. Sun stopped developping Xview further in about 1995. Meanwhile it has been replaced by more modern tools like Motif, QT, and other packages. Xview is still available and comes with some Linux distributions. It might however be that it is not installed on your machine by default.

Felix Debian (.deb) and RPM package

To ease installation, I have generated very basic .deb and .rpm packages. The debian package has been tested on a Kubuntu laptop and seemed to work. The rpm package is untested.

To install a package, download, right-click on it, and look for install options. USE AT YOUR OWN RISK. None of the packages is conform with the respective package maintainer standards. The RPM-package will not work if you don't have xview and xview-devel already installed (see below). The debian package should try downloading of missing packages.

Felix under Windows/Cygwin

It is possible to use Felix on a Windows machine. This requires that you have the Cygwin Linux emulator with gcc, XWin, and XView installed. Simulations are much slower than on a Linux machine but still usable, e.g., for lectures or presentations. You can find a Felix-version that works in a Cygwin environment HERE. Check the "readme.txt" file in thearchive for installation instructions.

   © 2004/2007 by -thowe-