A Bradford Book
The MIT Press
Cambridge, Massachusetts
London, England
Downloading the Exploration Simulations
The book contains over 40 simulations, which can be downloaded here
for free. The downloads include the simulator program, leabra++,
which is part of the The PDP++
Software. Most major platforms are supported. Click on the
appropriate link below to download the simulations for the associated
platform. Most of these files are roughly 14Mb, so they will take a
while to download over a slow link.
Next read this README
file on how to install the program after you've downloaded it.
For configuring multiple users on a unix system (e.g., for teaching), see README.multiusers
and multiusers_scripts.tar.
System Requirements
- RAM: 32Mb minimum, but 128Mb required for several larger
simulations.
- Disk: From 23Mb to over 30Mb depending on platform
(16Mb for just the simulations).
- Processor: Runs acceptably on a 166Mhz Pentium under Linux
(system used for textbook development), but faster is better,
especially under MS Windows.
- Display: (Important) minimum resolution 1024x768, 8bit
color (16bit preferred).
Updates and Version Numbers
Current version: 1.31 (most platforms)
We will be regularly fixing any bugs that are encountered in the
simulations or the simulation software. Therefore, you should
check back regularly to this site to see if there have been any
updates, especially if you notice any problems. The changes and
associated version numbers will be added to the following list
(version numbers appear in the downloaded file name, e.g.,
sims_1.10_LINUX.tar.gz is the 1.10 version of the simulations
for LINUX). If you find a bug that has not been fixed with a new
version, please email the details (enough to reliably reproduce the
bug) to
.
ChangeLog
(listed by date with most recent changes at the top, and changes
associated with a version appearing below that version release entry.
Changes are listed as the files affected (which may not be meaningful
to most users), followed by a description of what was fixed (which
should be meaningful)):
2003-04-23
version 1.31 released (most platforms): includes new pdp++ 3.02 binaries -- doesn't affect sims but might affect other projects.
2003-04-23
- version 1.30 released (all platforms): including all changes
below, with final 3.0 executables.
- chapter_6/rl_cond.proj.gz: graph log now uses trace increment
and trace_colors to better see what is happening with the DA
spikes.
- chapter_10/dyslex.proj.gz: lesion graph log uses stacked traces
to better see data.
- chapter_11/stroop.proj.gz: SOA log uses trace colors to better
distinguish the different cases. Also, stopping based on cycles
needed to be fixed for 3.0 (mon_vals[0] now has stopcrit instead
of mon -- various scripts needed to be updated as well.)
- all projects: updated for pdp++ 3.0, with the following general
changes:
- THREE_D is now the default value display in NetView
- Layer font size set to 18 in most cases, unit font = 14
- Graph lines width set to 2 (thicker, easier to see)
- Configured project window (usually hidden) to fit menus
2002-03-31
- chapter_8/objrec.proj.gz: the V2 off-center receptive field
displays for each unit were top-bottom mirror reversed -- this is
fixed.
2002-03-08
- chapter_3/inhib.proj.gz: fixed bug in KWTA_ inhibition modes,
where unit inhibition was still contributing (so you can now
combine kwta and unit inhib, but this is not what we want here).
Now, when you switch from UNIT_INHIB to one of the KWTA modes, it
automatically sets the scale.ff and .fb to 0, effectively turning
off the unit inhib.
2002-01-16
- Version 1.20 released (all platforms): includes new executables
(2.2 version of pdp++) and simulations updated in minor ways (some
more Step & StepCycle buttons).
- chapter_10/dyslex.proj.gz: the simple whole-pathway lesions (using the
lesion menu) in this project did not work correctly due to a bug with the
layer lesion flag in pdp++ 2.1 -- this is now fixed w/2.2.
- chapter_2/unit_ctrl.css: fixed UseBioVm, UseStdVm buttons to
actually switch log views under MS windows (removed dependency on
IsMapped() call, which doesn't work apparently).
2001-09-08
- Version 1.10 released (all platforms): includes new executables
(2.1 version of pdp++) and simulations updated. Primary changes =
new Step buttons on many simulations that previously lacked them.
Also, darker graphlog background should make things more visible.
2001-04-04
- Version 1.07 released (all platforms)
- leabra++.exe (MS Windows only) -- fixed size of windows to
be smaller to better fit the linux/unix sizes. Also fixed
paths of projects loaded from other directories to remove
the path because the system changes to that directory
already. Also updated to cygwin1.1.18.dll and associated
recent versions of gzip.exe and sh.exe.
- chapter_11/stroop.proj.gz: fixed stroop model to be less
sensitive to the random seed, which was different in the windows
version. Set the initial weight variance to zero, and set the
order of event presentation to be SEQUENTIAL instead of PERMUTED.
Small networks like this can be very sensitive in ways that are
not true for larger scale models where much more averaging can
take place.
2000-11-07
- Version 1.06 released (MS Windows only) -- fixed bug in
highlighting 'View'ed unit for viewing weights in NetView (it was
selecting the unit to the right of the actual unit, even though
the weights viewed were from the correctly selected unit.
- chapter_10/sem_ctrl.css: Fixed bug in displaying the cosine
differences in the WordMatrix function -- it was relying on the
"more" command which is not installed on MS Windows. Rewrote this
to display using basic C routines, and also it now pulls up a
GridLog with the actual cosine values.
2000-10-04
- Version 1.05 released (MS Windows only) -- fixed a bug in pdp++
that prevented NewInit from working properly. This caused the
necker cube project to do the same thing every time, instead of
settling into different interpretations. Other simulations were
undoubtedly also affected.
- The LINUXPPC version is now available!
2000-09-28
- Version 1.04 released (MS Windows only) -- moved
necker_cube_win.proj.gz to necker_cube.proj.gz (has cubes in
right place for windows).
2000-09-19
- Version 1.03 released (all platforms).
- chapter_10/sg_env.css: fixed bug that would display the following msg:
No current 'this' pointer, >2253 if(InheritsFrom("ScriptEnv")) {
whenver the network was run from the train process. result was that
training did not work!
2000-09-06
- Version 1.02 released (all platforms).
- chapter_10/*_ctrl.css, chapter_9/hipstu_ctrl.css,
chapter_8/objrec*_ctrl.css: all projects that have a BuildNet or
LoadNet now select "act" to view after building, which is what
the text expects.
2000-08-31
- Version 1.01 released (MS Windows only).
- README files now end in .txt for windows version, so notepad
will open them by default.
- chapter_9/hip.proj.gz: Fixed bug where testing text log was not
being updated in the windows version.
2000-08-11
Last updated: 04/21/03