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Subject: Re: Question for the MTD(f) experts

Author: Fabien Letouzey

Date: 02:11:29 04/15/04

Go up one level in this thread

On April 14, 2004 at 13:33:38, Robert Hyatt wrote:

>On April 14, 2004 at 03:30:22, Dann Corbit wrote:
>>I decided to toss an MTD(f) search into TSCP, and I've got something wrong, but
>>I can't quite see what it is.
>There is a lot more to do.
>1.  you need to modify the hash table to store 2 bounds, not 1.
>2.  the search must be fail-soft.  TSCP isn't.
>3.  PV has to be yanked from the hash table and that makes it flakey at times as
>has been discussed many times.  There is another way to get the PV, but it is a
>special case solution only for mtd...
>4.  the convergence has to be accelerated.  IE on a fail high searching v and
>v+1 won't cut it.
>IE this is not a "drop in and go" it is a "rewrite and test" thing to do. :)

Could you give me a pointer on the special way to get the PV (not with hash
tables)?  I'm interested in the preconditions.

I think 5) rounding the eval to the nearest multiple of whatever is also common.
Maybe it's a very small gain but I think most MTD(f) engines do this, unless
their eval has large grain to start with.


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