This is an important problem since, in some approaches, patterns will be stored as lists.
There are three issues/limitations to your solution below: - it uses one of the many possible distance metrics - items in a list may have different weights or relative importance (e.g. activation levels) - you assume equal weights in your formula. - it is really for sets rather than lists. If one uses a list instead of a set, then there is an explicit ordering element (the list index). This order may be very important or just a minor issue. Swopping two characters in a word is less important than swopping two notes in a tune, which is in turn far less of an issue than swopping cause and effect in a chain-reaction list. So a good similarity index will be dependent on context. Similar arguments for deleting or adding an element. Jean-Paul Van Belle ________________________________ From: Piaget Modeler [[email protected]] Sent: 20 February 2014 20:20 To: AGI Subject: RE: [agi] List Similarity (correction) The problem is much easier given two lists ; Premise code (c) 2014 Michael S P Miller function list-similarity {?A ?B} (put (length (intersection ?A ?B)) ?LenAnB) (put (length (difference ?A ?B)) ?LenA-B) (put (length (difference ?B ?A)) ?LenB-A) (put (length ?A) ?LenA) (put (length ?B) ?LenB) (return (if (or (= ?LenA 0)(= ?LenB 0)) 0 else (* 0.5 (- (+ (/ ?LenAnB ?LenA) (/ ?LenAnB ?LenB)) (+ (/ ?LenA-B ?LenA) (/ ?LenB-A ?LenB)))))) end For numbers, it's a little more difficult. Your thoughts? AGI | Archives<https://www.listbox.com/member/archive/303/=now> [https://www.listbox.com/images/feed-icon-10x10.jpg] <https://www.listbox.com/member/archive/rss/303/19999924-4a978ccc> | Modify<https://www.listbox.com/member/?&;> Your Subscription [https://www.listbox.com/images/listbox-logo-small.png] <http://www.listbox.com> AGI | Archives<https://www.listbox.com/member/archive/303/=now> [https://www.listbox.com/images/feed-icon-10x10.jpg] <https://www.listbox.com/member/archive/rss/303/5404257-22a42d7f> | Modify<https://www.listbox.com/member/?&;> Your Subscription [https://www.listbox.com/images/listbox-logo-small.png] <http://www.listbox.com> ________________________________ UNIVERSITY OF CAPE TOWN This e-mail is subject to the UCT ICT policies and e-mail disclaimer published on our website at http://www.uct.ac.za/about/policies/emaildisclaimer/ or obtainable from +27 21 650 9111. This e-mail is intended only for the person(s) to whom it is addressed. If the e-mail has reached you in error, please notify the author. If you are not the intended recipient of the e-mail you may not use, disclose, copy, redirect or print the content. If this e-mail is not related to the business of UCT it is sent by the sender in the sender's individual capacity. ------------------------------------------- AGI Archives: https://www.listbox.com/member/archive/303/=now RSS Feed: https://www.listbox.com/member/archive/rss/303/21088071-f452e424 Modify Your Subscription: https://www.listbox.com/member/?member_id=21088071&id_secret=21088071-58d57657 Powered by Listbox: http://www.listbox.com
