http://www.sai.msu.su/~megera/postgres/gist/tsearch/V2/docs/tsearch2-ref.html > >what's about simple normalization formulae, like rank/(rank+1) ? > >I think you are suggesting that I use the best rank as the denominator > >for the rank column. Yes, I suppose that will work. > > 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. id | headline | rank ----+-------------------------------------------------------+------ 3 | <b>crawling</b> over cobbles in a low <b>passage</b>. | 0.19 1 | <b>crawl</b> over cobbles leads inward to the west. | 0.1 4 | <b>passages</b> lead east, north, and south. | 0.1 5 | <b>crawl</b> slants up. | 0.1 7 | <b>passage</b> here is blocked by a recent cave-in. | 0.1 Am I being stupid? [1] http://www.sai.msu.su/~megera/postgres/gist/tsearch/V2/docs/tsearch2-guide.html -- Make April 15 just another day, visit http://fairtax.org
