Re: fuzzy unification of floating point numbers

Article View: comp.lang.prolog

Article #628

#628

From: Jonny Farringdon
Date: Thu, 13 Aug 1992 13:39

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>Does anybody know the prolog for UNIX which supports
>the fuzzy unification of floating point numbers,     
>that is two floating point numbers are considered 
>equal if | X - Y | =< FUZZVALUE  and this FUZZVALUE
>can be changed by user? I know that VM/Prolog has
>this feature, but it works on mainframe.
>Any information is appreciated.

Mike,

each time you want to do

thing(A,B) :- 
    a = b, 
    important_thing.

do:

thing(A,B) :-
    fuzzy_equality_test(A,B),
    important_thing.

fuzzy_equality_test(A,B) :-
    fuzzy_unify_value(V), !,
    Diff is A - B,
    absolute_value(Diff,Abs_Diff),
    Abs_Diff < V.

fuzzy_equality_test(A,A) :- !.

J.  ucjtrjf@ucl.ac.uk

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Message-ID: <1992Aug13.133930.25900@bas-a.bcc.ac.uk>

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References: <1992Aug12.210954.15241@cs.ucla.edu>

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Path: arc1-ca.pugleaf.net!sparky!uunet!mcsun!uknet!bcc.ac.uk!link-1.ts.bcc.ac.uk!ucjtrjf
From: ucjtrjf@ucl.ac.uk (Jonny Farringdon)
Newsgroups: comp.lang.prolog
Subject: Re: fuzzy unification of floating point numbers
Message-ID: <1992Aug13.133930.25900@bas-a.bcc.ac.uk>
Date: 13 Aug 92 13:39:30 GMT
References: <1992Aug12.210954.15241@cs.ucla.edu>
Organization: Bloomsbury Computing Consortium
Lines: 31

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