strgrp: Add cosine fudge-curve to unify filter comparison spaces
authorAndrew Jeffery <andrew@aj.id.au>
Sat, 20 Feb 2016 10:52:41 +0000 (21:22 +1030)
committerAndrew Jeffery <andrew@aj.id.au>
Fri, 25 Mar 2016 12:39:32 +0000 (23:09 +1030)
commite8f7a978bf4eb41c1877958e31a1a7213680335b
tree16b747804745baf40375b98ed581f4f0d6c49088
parent911a66a7893ca7c8b225a1b5fd5ec55569b12632
strgrp: Add cosine fudge-curve to unify filter comparison spaces

If we are to use should_grp_score_cos(x,y) as a filter the the following
relationship must hold (from least to most expensive):

        should_grp_score_len(x,y)
                >= should_grp_score_cos(x,y)
                >= grp_score(x)

should_grp_score_cos(x,y) wasn't holding up its part of the bargain, so
real data was used to generate a fudge curve to bring
should_grp_score_cos(x,y) results into the same space. Really this is a
terrible hack and the problem needs more thought. Evaluation of
should_grp_score_cos(x,y)'s performance benefit (given the relaxation of
the filter under the fudge curve) is sorely needed.
ccan/strgrp/_info
ccan/strgrp/strgrp.c