------- OFFICIAL RELEASE! All pre-release 5.0 versions should be deleted ------- The following describes a neural network simulation environment made available free from the MITRE Corporation. The software contains a neural network simulation code generator which generates high performance C code implementations for backpropagation networks. Also included is an interface to visualization tools. FREE NEURAL NETWORK SIMULATOR AVAILABLE Aspirin/MIGRAINES Version 5.0 The Mitre Corporation is making available free to the public a neural network simulation environment called Aspirin/MIGRAINES. The software consists of a code generator that builds neural network simulations by reading a network description (written in a language called "Aspirin") and generates a C simulation. An interface (called "MIGRAINES") is provided to export data from the neural network to visualization tools. The system has been ported to a number of platforms: Apollo Convex Cray DecStation HP IBM RS/6000 Intel 486/386 (Unix System V) NeXT News Silicon Graphics Iris Sun4, Sun3 Coprocessors: Mercury i860 (40MHz) Coprocessors Meiko Computing Surface w/i860 (40MHz) Nodes Skystation i860 (40MHz) Coprocessors iWarp Cells Included with the software are "config" files for these platforms. Porting to other platforms may be done by choosing the "closest" platform currently supported and adapting the config files. Aspirin 5.0 ------------ The software that we are releasing now is for creating, and evaluating, feed-forward networks such as those used with the backpropagation learning algorithm. The software is aimed both at the expert programmer/neural network researcher who may wish to tailor significant portions of the system to his/her precise needs, as well as at casual users who will wish to use the system with an absolute minimum of effort. Aspirin was originally conceived as ``a way of dealing with MIGRAINES.'' Our goal was to create an underlying system that would exist behind the graphics and provide the network modeling facilities. The system had to be flexible enough to allow research, that is, make it easy for a user to make frequent, possibly substantial, changes to network designs and learning algorithms. At the same time it had to be efficient enough to allow large ``real-world'' neural network systems to be developed. Aspirin uses a front-end parser and code generators to realize this goal. A high level declarative language has been developed to describe a network. This language was designed to make commonly used network constructs simple to describe, but to allow any network to be described. The Aspirin file defines the type of network, the size and topology of the network, and descriptions of the network's input and output. This file may also include information such as initial values of weights, names of user defined functions. The Aspirin language is based around the concept of a "black box". A black box is a module that (optionally) receives input and (necessarily) produces output. Black boxes are autonomous units that are used to construct neural network systems. Black boxes may be connected arbitrarily to create large possibly heterogeneous network systems. As a simple example, pre or post-processing stages of a neural network can be considered black boxes that do not learn. The output of the Aspirin parser is sent to the appropriate code generator that implements the desired neural network paradigm. The goal of Aspirin is to provide a common extendible front-end language and parser for different network paradigms. The publicly available software will include a backpropagation code generator that supports several variations of the backpropagation learning algorithm. For backpropagation networks and their variations, Aspirin supports a wide variety of capabilities: 1. feed-forward layered networks with arbitrary connections 2. ``skip level'' connections 3. one and two-dimensional weight tessellations 4. a few node transfer functions (as well as user defined) 5. connections to layers/inputs at arbitrary delays, also "Waibel style" time-delay neural networks 6. autoregressive nodes. 7. line search and conjugate gradient optimization The file describing a network is processed by the Aspirin parser and files containing C functions to implement that network are generated. This code can then be linked with an application which uses these routines to control the network. Optionally, a complete simulation may be automatically generated which is integrated with the MIGRAINES interface and can read data in a variety of file formats. Currently supported file formats are: Ascii Type1, Type2, Type3 Type4 Type5 (simple floating point file formats) ProMatlab Examples -------- A set of examples comes with the distribution: xor: from RumelHart and McClelland, et al, "Parallel Distributed Processing, Vol 1: Foundations", MIT Press, 1986, pp. 330-334. encode: from RumelHart and McClelland, et al, "Parallel Distributed Processing, Vol 1: Foundations", MIT Press, 1986, pp. 335-339. detect: Detecting a sine wave in noise. iris: The classic iris database. characters: Learing to recognize 4 characters independent of rotation. ring: Autoregressive network learns a decaying sinusoid impulse response. sequence: Autoregressive network learns to recognize a short sequence of orthonormal vectors. sonar: from Gorman, R. P., and Sejnowski, T. J. (1988). "Analysis of Hidden Units in a Layered Network Trained to Classify Sonar Targets" in Neural Networks, Vol. 1, pp. 75-89. spiral: from Kevin J. Lang and Michael J, Witbrock, "Learning to Tell Two Spirals Apart", in Proceedings of the 1988 Connectionist Models Summer School, Morgan Kaufmann, 1988. ntalk: from Sejnowski, T.J., and Rosenberg, C.R. (1987). "Parallel networks that learn to pronounce English text" in Complex Systems, 1, 145-168. perf: a large network used only for performance testing. monk: The backprop part of the monk paper. The MONK's problem were the basis of a first international comparison of learning algorithms. The result of this comparison is summarized in "The MONK's Problems - A Performance Comparison of Different Learning algorithms" by S.B. Thrun, J. Bala, E. Bloedorn, I. Bratko, B. Cestnik, J. Cheng, K. De Jong, S. Dzeroski, S.E. Fahlman, D. Fisher, R. Hamann, K. Kaufman, S. Keller, I. Kononenko, J. Kreuziger, R.S. Michalski, T. Mitchell, P. Pachowicz, Y. Reich H. Vafaie, W. Van de Welde, W. Wenzel, J. Wnek, and J. Zhang has been published as Technical Report CS-CMU-91-197, Carnegie Mellon University in Dec. 1991. Performance of Aspirin simulations ---------------------------------- The backpropagation code generator produces simulations that run very efficiently. Aspirin simulations do best on vector machines when the networks are large, as exemplified by the Cray's performance. All simulations were done using the Unix "time" function and include all simulation overhead. The connections per second rating was calculated by multiplying the number of iterations by the total number of connections in the network and dividing by the "user" time provided by the Unix time function. Two tests were performed. In the first, the network was simply run "forward" 100,000 times and timed. In the second, the network was timed in learning mode and run until convergence. Under both tests the "user" time included the time to read in the data and initialize the network. Sonar: This network is a two layer fully connected network with 60 inputs: 2-34-60. Millions of Connections per Second Forward: SparcStation1: 1 IBM RS/6000 320: 2.8 HP9000/730: 4.0 Meiko i860 (40MHz) : 4.4 Mercury i860 (40MHz) : 5.6 Cray YMP: 21.9 Cray C90: 33.2 Forward/Backward: SparcStation1: 0.3 IBM RS/6000 320: 0.8 Meiko i860 (40MHz) : 0.9 HP9000/730: 1.1 Mercury i860 (40MHz) : 1.3 Cray YMP: 7.6 Cray C90: 13.5 Gorman, R. P., and Sejnowski, T. J. (1988). "Analysis of Hidden Units in a Layered Network Trained to Classify Sonar Targets" in Neural Networks, Vol. 1, pp. 75-89. Nettalk: This network is a two layer fully connected network with [29 x 7] inputs: 26-[15 x 8]-[29 x 7] Millions of Connections per Second Forward: SparcStation1: 1 IBM RS/6000 320: 3.5 HP9000/730: 4.5 Mercury i860 (40MHz) : 12.4 Meiko i860 (40MHz) : 12.6 Cray YMP: 113.5 Cray C90: 220.3 Forward/Backward: SparcStation1: 0.4 IBM RS/6000 320: 1.3 HP9000/730: 1.7 Meiko i860 (40MHz) : 2.5 Mercury i860 (40MHz) : 3.7 Cray YMP: 40 Cray C90: 65.6 Sejnowski, T.J., and Rosenberg, C.R. (1987). "Parallel networks that learn to pronounce English text" in Complex Systems, 1, 145-168. Perf: This network was only run on a few systems. It is very large with very long vectors. The performance on this network is in some sense a peak performance for a machine. This network is a two layer fully connected network with 2000 inputs: 100-500-2000 Millions of Connections per Second Forward: Cray YMP 103.00 Cray C90 220 Forward/Backward: Cray YMP 25.46 Cray C90 59.3 MIGRAINES ------------ The MIGRAINES interface is a terminal based interface that allows you to open Unix pipes to data in the neural network. This replaces the NeWS1.1 graphical interface in version 4.0 of the Aspirin/MIGRAINES software. The new interface is not a simple to use as the version 4.0 interface but is much more portable and flexible. The MIGRAINES interface allows users to output neural network weight and node vectors to disk or to other Unix processes. Users can display the data using either public or commercial graphics/analysis tools. Example filters are included that convert data exported through MIGRAINES to formats readable by: - Gnuplot 3.0 - Matlab - Mathematica Most of the examples (see above) use the MIGRAINES interface to dump data to disk and display it using a public software package called Gnuplot3.0. Gnuplot3.0 can be obtained via anonymous ftp from: >>>> In general, Gnuplot 3.0 is available as the file gnuplot3.0.tar.Z. >>>> Please obtain gnuplot from the site nearest you. Many of the major ftp >>>> archives world-wide have already picked up the latest version, so if >>>> you found the old version elsewhere, you might check there. >>>> >>>> >>>> USENET users: >>>> >>>> GNUPLOT 3.0 was posted to comp.sources.misc. >>>> >>>> >>>> NORTH AMERICA: >>>> >>>> Anonymous ftp to dartmouth.edu (129.170.16.4) >>>> Fetch >>>> pub/gnuplot/gnuplot3.0.tar.Z >>>> in binary mode. >>>>>>>> A special hack for NeXTStep may be found on 'sonata.cc.purdue.edu' >>>>>>>> in the directory /pub/next/submissions. The gnuplot3.0 distribution >>>>>>>> is also there (in that directory). >>>>>>>> >>>>>>>> There is a problem to be aware of--you will need to recompile. >>>>>>>> gnuplot has a minor bug, so you will need to compile the command.c >>>>>>>> file separately with the HELPFILE defined as the entire path name >>>>>>>> (including the help file name.) If you don't, the Makefile will over >>>>>>>> ride the def and help won't work (in fact it will bomb the program.) NetTools ----------- We have include a simple set of analysis tools by Simon Dennis and Steven Phillips. They are used in some of the examples to illustrate the use of the MIGRAINES interface with analysis tools. The package contains three tools for network analysis: gea - Group Error Analysis pca - Principal Components Analysis cda - Canonical Discriminants Analysis How to get Aspirin/MIGRAINES ----------------------- The software is available from two FTP sites, CMU's simulator collection and UCLA's cognitive science machines. The compressed tar file is a little less than 2 megabytes. Most of this space is taken up by the documentation and examples. The software is currently only available via anonymous FTP. > To get the software from CMU's simulator collection: 1. Create an FTP connection from wherever you are to machine "pt.cs.cmu.edu" (128.2.254.155). 2. Log in as user "anonymous" with password your username. 3. Change remote directory to "/afs/cs/project/connect/code". Any subdirectories of this one should also be accessible. Parent directories should not be. ****You must do this in a single operation****: cd /afs/cs/project/connect/code 4. At this point FTP should be able to get a listing of files in this directory and fetch the ones you want. Problems? - contact us at "connectionists-request@cs.cmu.edu". 5. Set binary mode by typing the command "binary" ** THIS IS IMPORTANT ** 6. Get the file "am5.tar.Z" > To get the software from UCLA's cognitive science machines: 1. Create an FTP connection to "polaris.cognet.ucla.edu" (128.97.50.3) (typically with the command "ftp 128.97.50.3") 2. Log in as user "anonymous" with password your username. 3. Change remote directory to "alexis", by typing the command "cd alexis" 4. Set binary mode by typing the command "binary" ** THIS IS IMPORTANT ** 5. Get the file by typing the command "get am5.tar.Z" How to unpack the software -------------------------- After ftp'ing the file make the directory you wish to install the software. Go to that directory and type: zcat am5.tar.Z | tar xvf - -or- uncompress am5.tar.Z ; tar xvf am5.tar How to print the manual ----------------------- The user documentation is located in ./doc in a few compressed PostScript files. To print each file on a PostScript printer type: uncompress *.Z lpr -s *.ps Why? ---- I have been asked why MITRE is giving away this software. MITRE is a non-profit organization funded by the U.S. federal government. MITRE does research and development into various technical areas. Our research into neural network algorithms and applications has resulted in this software. Since MITRE is a publically funded organization, it seems appropriate that the product of the neural network research be turned back into the technical community at large. Thanks ------ Thanks to the beta sites for helping me get the bugs out and make this portable. Thanks to the folks at CMU and UCLA for the ftp sites. Copyright and license agreement ------------------------------- Since the Aspirin/MIGRAINES system is licensed free of charge, the MITRE Corporation provides absolutely no warranty. Should the Aspirin/MIGRAINES system prove defective, you must assume the cost of all necessary servicing, repair or correction. In no way will the MITRE Corporation be liable to you for damages, including any lost profits, lost monies, or other special, incidental or consequential damages arising out of the use or in ability to use the Aspirin/MIGRAINES system. This software is the copyright of The MITRE Corporation. It may be freely used and modified for research and development purposes. We require a brief acknowledgement in any research paper or other publication where this software has made a significant contribution. If you wish to use it for commercial gain you must contact The MITRE Corporation for conditions of use. The MITRE Corporation provides absolutely NO WARRANTY for this software. January, 1992 Russell Leighton * * MITRE Signal Processing Center *** *** *** *** 7525 Colshire Dr. ****** *** *** ****** McLean, Va. 22102, USA ***************************************** ***** *** *** ****** INTERNET: russ@dash.mitre.org, ** *** *** *** leighton@mitre.org * *