[ACT-R-users] New ACT-R software release available

[db30 at andrew.cmu.edu]

A new version of the ACT-R 7 software is now available from the
ACT-R website: <http://act-r.psy.cmu.edu/software/>.  The current
version is now 7.3-<2102:2016-12-20>.

A few of the notable changes are listed below.  More details
can be found in the commit log found on the ACT-R website at:
<http://act-r.psy.cmu.edu/log/actr6log.txt>, but only the changes
in the actr7 branch are relevant to the current software.

Production compilation has been updated to better handle buffers
which are strict harvested.  It is now safer because it will not
compose productions which have a stuffed chunk between them for
goal and imaginal type buffers in cases where strict harvesting
was the reason the buffer cleared in the first production.  It
also produces better composed productions in situations were
strict harvesting clears the buffer and the second production
tests that it is empty.  Previously the 'buffer empty' query from
the second production was added to the composed production, but
that prevents the composed production from competing with the
first parent.  Now that query is dropped from the new production.

The mod-focus command now makes the modification during the
goal-modification event instead of directly.  This allows one to use
goal-focus followed by a mod-focus without it complaining that the
buffer is empty.

Added an extra which implements a modification to the activation
calculation for declarative memory.  The purpose of the modifiction
is to decrease the effect of noise on the activation of chunks as
their activation increases with practice.  The extras/adaptive-noise
directory contains the code which adds a parameter called :uan
(use adaptive-noise) that can be set to t to enable the mechanism.
The documentation included with the extra describes how it works,
and there are some sample graphs of the results of some very simple
test cases showing the change when :uan is enabled.


If you have any questions or problems with the new version please let
me know.

Dan