Re: scoring differences between bitmasks - Mailing list pgsql-general

From Martijn van Oosterhout
Subject Re: scoring differences between bitmasks
Date
Msg-id 20051002195037.GK30492@svana.org
Whole thread Raw
In response to scoring differences between bitmasks  (Ben <bench@silentmedia.com>)
List pgsql-general
On Sun, Oct 02, 2005 at 10:17:10AM -0700, Ben wrote:
> Yeah, I thought about this, but damn my 3-dimensional mind, I just
> can't convince myself this will work for 256 dimensions. :) Or
> rather, I can see how it could, *given* good placements of the grid
> points to snap each vector to. Unfortunately, I don't know enough
> theory to know what good placements would be.

My intuition tells me that just like real life, you want them to be as
far apart as possible. That's why I picked those strings. If the string
is length N, all those key strings are distance n/2 apart from
eachother.

As for proof, I think it will work due to the triangle inequality
holding true. Try not to worry about the dimensions, if you don't
assume the number of dimensions, it'll work for any.

My Google search hasn't come up with anything, although searching for
"binary vector space search" comes with some almost but not quite
results.

Good luck...
--
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.

Attachment

pgsql-general by date:

Previous
From: Ben
Date:
Subject: Re: scoring differences between bitmasks
Next
From: Wes
Date:
Subject: Re: 8.1 'make check' fails