Bb2 optimization

Optimization of the BB2 scheme.
I know . but this is the best I could do. it fails at both wdf upper and
wdf lower and the differentiation gives nothing indicative .
On 24/06/2014 10:03 am, "Olly Betts" <notifications@github.com> wrote:

> In xapian-core/weight/bb2weight.cc:
>
> >
> > -    double final_weight_max = B_max * (weight_max + stirling_max);
> > +    double stirling_max = stirling_max_term1 - stirling_min_term2;
>
> I suspect you're aware, but if A(x) = B(x) - C(x), then max(B(x)) -
> min(C(x)) may not be a tight bound on A(x), since max(B(x)) and min(C(x))
> are probably at different values of x. It does at least provide a valid
> upper bound though.
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/xapian/xapian/pull/43/files#r14112608>.
>