On 2017/06/23 6:28, Alvaro Herrera wrote:
> Ashutosh Bapat wrote:
>> On Mon, Jun 5, 2017 at 8:22 AM, atorikoshi
>> <torikoshi_atsushi_z2@lab.ntt.co.jp> wrote:
>>> Hi,
>>>
>>> I found below formula to compute selectivities, but
>>> I think the last Probability 'P(b=?)' should be 'P(c=?)'.
>>>
>>>> P(a=?,b=?,c=?) = P(a=?,b=?) * (d + (1-d)*P(b=?))
>>>
>>>
>>> Attached patch fixes it, and it also adds some spaces
>>> following another formula which is on line 86 and
>>> computes P(a=?, b=?).
>>
>> Agree. Also using "d" for "degree of functional dependence (b=>c) as
>> well is confusing. We are already using "d" for "degree of functional
>> dependence (a=>b). Here' patch to use "d'" instead of "d".
>
> Since the surrounding text uses single quotes to talk about each letter,
> I thought it was better to use a new letter (e) so that we don't require
> the "prime" notation, which would end up being either inconsistent,
> confusing, stupid-looking, or combinations thereof.
>
> Also, your proposed text had a slight mistake: it's not (b=>c) that
> d' is for, but (a,b=>c).
>
> Pushed with those corrections.
>
> Thanks for the reports and patches!
>
Thanks!
--
Atsushi Torikoshi
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center