barshay@Stars.Reston.Unisys.COM ( Unisys) (09/19/90)
Hi,
Thanks to everyone who posted and mailed responses
to my CLIPS v. NEXPERT question! I've been playing with
CLIPS and find it really simple to use with some of the
clearest documentation I have ever used. I can not comment
on the performance issues as I have not used it extensively.
Our customer has indicated that despite my praise for CLIPS ...
we will be using NEXPERT for our application. I will try to
post again after using NEXPERT for a while and give you my
opinions. I'm afraid they were influenced by the flashy demo.
(although I am curious about the SQL interface that I heard
NEXPERT is incorporating in their latest release!)
If anyone would like a summary of all the discussion they
can write to me directly.
Thanks again.
Jane
CLIPS
Pros
------
C Source available makes it very flexible
Easy to learn - you can "Get going" right away
Easy to use for embedded applications (with good documention)
Easy to call C routines from within CLIPS
Uses Rete algorithm
Cons
------
Not object-oriented (changing in 5.0)
One user found it slow and a memory hog on the Sun 3/50
(this was with using only 10 rules)
Lack of backward chaining
----------------------------------------------------------------------------
NEXPERT
Pros
------
Easy to embed.
Agenda Monitor to observe inference engine
Graphical Interface
Cons
_____
This was a big complaint -
Documentation hard to understand (suggest taking formal training)
One user found forward chaining "tortuously" slow" with medium to large
rule base (doesn't use Rete alogorithm)
Object-Oriented features overrated because does not have message
sending capabilities
Rule editor is "cumbersome"
Debugging painful
Other products of interest!
---------------------------
Comments on Pro-Kappa by Intellicorp
ART-IM from Inference Corp.
Info on CLIPS and How to order
------------------------------
If anyone is interested in CLIPS, you might consider waiting a little bit.
NASA has come out with CLIPS v5.0 with lots of goodies.
CLIPS Object-Oriented Language (COOL) - "The features of COOL include:
classes with multiple inheritance, single and multi-valued slots (with
slot daemons), instances with encapsulation, and message-passing (with
before, after, primary, and around message-handlers)."
Deffunctions - "deffunctions may be used to new capabilities to CLIPS
without having to write new code in C and recompile CLIPS."
Generic functions - "Generic functions can be used to overload functions
in a manner similar to, but much more powerful than, languages such as
ADA and C++."
Global Variables
Integer Data Type Support
Conflict Resolution Strategies and Salience Extensions - "Seven conflict
resolution strategies are provided including depth, breadth, lex, mea,
simplicity, complexity, and random. ... Salience values can also be
dynamically evaluated each time a new activation is added to the agenda..."
Deftemplate Field Checking
Incremental Reset
Truth Maintenance - "Facts can be made logically dependent upon the
existence or nonexistence of other facts."
(quoted from CLIPS v5.0 announcement)
NASA, USAF, and their contractors can get CLIPS by calling the CLIPS
Help Desk at (713) 280-2233 (Mon - Fri). CLIPS v5.0 will be available
to the general public "by early 1991" (from the v5.0 announcement).
I heard from reliable sources that it would be January 1991.
The general public can obtain CLIPS from COSMIC (for $350):
COSMIC
382 E. Broad St.
Athens, GA 30602
(404) 542-3265
Andrew Warinner | "Semper ubi sub ubi" - J. Caesar
GIST, Inc. |
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