Author: Dave Gomboc
Date: 09:01:25 11/09/03
Go up one level in this thread
On November 08, 2003 at 11:09:35, Robert Hyatt wrote: >On November 07, 2003 at 14:14:58, Dave Gomboc wrote: > >>On November 07, 2003 at 14:14:08, Dave Gomboc wrote: >> >>>On November 06, 2003 at 22:31:49, Robert Hyatt wrote: >>> >>>>On November 06, 2003 at 20:43:58, Dave Gomboc wrote: >>>> >>>>>On November 06, 2003 at 19:46:29, Robert Hyatt wrote: >>>>> >>>>>>On November 06, 2003 at 11:22:54, Dave Gomboc wrote: >>>>>> >>>>>>>On November 06, 2003 at 09:47:32, Robert Hyatt wrote: >>>>>>> >>>>>>>>On November 06, 2003 at 08:33:49, Gian-Carlo Pascutto wrote: >>>>>>>> >>>>>>>>>On November 06, 2003 at 05:45:53, Renze Steenhuisen wrote: >>>>>>>>> >>>>>>>>>>Depth-First Algorithms: >>>>>>>>>> AlphaBeta (Fail-hard, Fail-Soft) >>>>>>>>>> MTD(f) >>>>>>>>>> >>>>>>>>>>Best-First Algorithms: >>>>>>>>>> SSS* >>>>>>>>> >>>>>>>>>The distinction between the three (and best-first and depth-first) >>>>>>>>>is very hazy, read "Research re: search and research" by Aske Plaat. >>>>>>>>> >>>>>>>>>-- >>>>>>>>>GCP >>>>>>>> >>>>>>>> >>>>>>>>Eh? The distinction is _huge_. >>>>>>>> >>>>>>>>One searches the tree in one direction and requires very little memory. The >>>>>>>>other searches the tree in another direction and requires huge memory. >>>>>>>> >>>>>>>>I'm not sure how you could say that the distinction is very hazy. They >>>>>>>>are as different as night and day... >>>>>>> >>>>>>>However, MTD(infinity) is equivalent to (searches exactly the same tree as) SSS. >>>>>> >>>>>> >>>>>>That's fine. A best-first (breadth-first) search can search _exactly_ >>>>>>the same tree as a minimax (depth-first) search also. Doesn't mean a >>>>>>thing about how similar the two approaches are, however... >>>>>> >>>>>>However, the trees are grown differently. I don't think any book I >>>>>>know of uses the actual search space as a way to define a search >>>>>>strategy... >>>>>> >>>>>> >>>>>>> >>>>>>>http://www.cs.ualberta.ca/~jonathan/Grad/plaat.phd.ps >>>>>>> >>>>>>>Dave >>>>> >>>>>Fine, but the point is that in this particular case, they are not as different >>>>>as night and day. :-) >>>>> >>>>>Dave >>>> >>>>They are different in the base algorithm. They are different in their >>>>memory requirements. They are different in the order in which they search >>>>the tree. They are different in how hashing may (or may not) work. >>> >>>They are *NOT* different in the order in which they search the tree. The >>>traversal order is identical. >> >>More accurately, the node expansion order is identical. >> >>DAve > > >Which specific depth-first vs breadth-first algorithms are you comparing >when you make that statement? The ones GCP mentioned: mtd(oo) and SSS. mtd(-oo) and DUAL also have identical node expansion order. Dave
This page took 0.01 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.