On Wed, Jul 04, 2007 at 11:08:21AM +0200, hubert depesz lubaczewski wrote:
> On 7/4/07, Joshua N Pritikin <jpritikin@pobox.com> wrote:
> >From where are you quoting? I was quoting from:
> >
> >http://www.sai.msu.su/~megera/postgres/gist/tsearch/V2/docs/tsearch2-ref.html
>
> i was quoting file
> http://www.sai.msu.su/~megera/postgres/gist/tsearch/V2/docs/tsearch-V2-intro.html
So that one is fine. Only the reference could use some clarification.
> >actually oleg supposed not to use best rank, but just use the formula as
> >> given - rank/(rank+1) to get rank in range of 0 to 1.
> >OK, then what does the +1 mean in your formulae? Consider these results
> >from [1]. rank/(rank+1): 0.19/.1 = 1.9, .1/.1 = 1, etc. That doesn't
> >make sense. The reciprocal also doesn't make sense. So what does Oleg
> >mean? I was guessing that Oleg meant to divide the rank column by the
> >first rank, that is, by 0.19 so you would get 1, .52, .52, etc.
>
> +1 means: add one to.
> for example: for rank = 0.1 you get: 0.1/(0.1+1) = 0.1/1.1 = 0.0909
> for rank = 0.5 you get: 0.5/(0.5+1) = 0.5/1.5 = 0.3333
D'oh! I see.
> i think that notation: rank+1 is pretty readable.
>
> additionally - sorry but i dont understand your calculations. what is
> 0.19/.1
> ? how did you get the .1?
I was imagining that "rank+1" was the second row of the rank column.
Sorry for the confusion.
--
Make April 15 just another day, visit http://fairtax.org