CODEWITHSUNDEEP
clips
melaos
melaos

Reputation: 8428

How to fire off the rule in this example?

I'm trying to build a simple expert system for recommending courses and want to implement certainty factor in my program, however I'm stuck looking for a simple integration method.

I've stumbled upon this example but can't seems to figure out how to make it fire.

; Allow facts that are duplicates:
(defrule start
(declare (salience 1000))
(initial-fact)
=>
(set-fact-duplication TRUE))

(defrule combine-certainities-both-positive
?fact1 <- (organism ?attribute ?value ?C1&:(>= ?C1 0))
?fact2 <- (organism ?attribute ?value ?C2&:(>= ?C2 0))
(test (neq ?fact1 ?fact2))
=>
(retract ?fact1 ?fact2)
(bind ?C3 (- (+ ?C1 ?C2) (* ?C1 ?C2)))
(assert (organism ?attribute ?value ?C3)))

(defrule combine-certainities-both-negative
?fact1 <- (organism ?attribute ?value ?C1&:(< ?C1 0))
?fact2 <- (organism ?attribute ?value ?C2&:(< ?C2 0))
(test (neq ?fact1 ?fact2))
=>
(retract ?fact1 ?fact2)
(bind ?C3 (+ (+ ?C1 ?C2) (* ?C1 ?C2)))
(assert (organism ?attribute ?value ?C3)))

(defrule combine-certainities-with-opposite-signs
?fact1 <- (organism ?attribute ?value ?C1)
?fact2 <- (organism ?attribute ?value ?C2)
(test (< (* ?C1 ?C2) 0))
(test (neq ?fact1 ?fact2))
=>
(retract ?fact1 ?fact2)
(bind ?C3 (/ (+ ?C1 ?C2) (- 1 (min (abs ?C1) (abs ?C2)))))
(assert (organism ?attribute ?value ?C3)))

I try to assert two new organism facts to kick start the first rule:

CLIPS> (assert (organism morpholgy1 rod1 0.25)
(organism morpholgy2 rod2 0.25))
==> f-4     (organism morpholgy1 rod1 0.25)
==> f-5     (organism morpholgy2 rod2 0.25)
<Fact-5>
CLIPS> (run)
<== Focus MAIN
0 rules fired        Run time is 0.00300693511962891 seconds.
0.0 rules per second.
2 mean number of facts (2 maximum).
0 mean number of instances (0 maximum).
0 mean number of activations (0 maximum).

And use the matches but still don't get how to make it match here..

CLIPS> (matches combine-certainities-both-positive)
Matches for Pattern 1
f-4
f-5
Matches for Pattern 2
f-4
f-5
Partial matches for CEs 1 - 2
 None
Activations
 None
(4 0 0)

Upvotes: 0

Views: 75

Answers (1)

Gary Riley
Gary Riley

Reputation: 10757

The attribute and the value have to match (morpholgy1 != morpholgy2 and rod1 != rod2). That's why fact duplication has to be enabled to allow multiple copies of the same attribute/value.

CLIPS> (set-fact-duplication TRUE)
FALSE
CLIPS> 
(assert (organism morpholgy rod 0.25)
        (organism morpholgy rod 0.25))
<Fact-2>
CLIPS> (watch facts)
CLIPS> (run)
<== f-2     (organism morpholgy rod 0.25)
<== f-1     (organism morpholgy rod 0.25)
==> f-3     (organism morpholgy rod 0.4375)
CLIPS>

Upvotes: 1

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