Re: [boost] [time_series] Review

From: Eric Niebler (eric_at_[hidden])
Date: 2007-08-12 15:04:43

Zach Laine wrote:
> On 8/10/07, Eric Niebler <eric_at_[hidden]> wrote:
>> Discretization for the other series types is not useless. For sparse,
>> for example, it enforces that samples may only exist at offsets that are
>> a multiple of the discretization.
> 
> I was reading the rest of your email and having a hard time understand
> how we were talking past each other so completely.  Here is where I
> could first figure out how we'd gotten out of phase.  I was operating
> under the impression that sparse series could have values at arbitrary
> offsets (not integer multiples of the discretization).  It was this
> misunderstanding on my part that lead to my suggestion to remove
> discretization from some types.  Consider it withdrawn.  Though you're
> probably sick of hearing this, the use of discretization should be
> spelled out more explicitly in the documentation to make this clear.

OK, I think we're on the same page now, but just to clarify the 
situation, the following two series are identical:

sparse_series<int> s( discretization = 5 );
dense_series<int> d( discretization = 5 );

make_ordered_inserter(s)(1,1)(2,2)(3,3).commit();
make_ordered_inserter(d)(1,1)(2,2)(3,3).commit();

These both have a 1 at offset 1, a 2 at offset 2 and a 3 at offset 3. 
The offsets represent T=0,5,10 respectively due to the discretization. 
Because the discretization is a logical multiplicative factor of the 
offsets, the sparse series is guaranteed to have values only at points 
that are multiples of the discretization; that is, T=0,5,10.

The docs have a ways to go to make this clear, I agree. But now that its 
clear and your suggestion is withdrawn, is your objection to the time 
series library also withdrawn?

-- 
Eric Niebler
Boost Consulting
www.boost-consulting.com
The Astoria Seminar ==> http://www.astoriaseminar.com