Zach Laine wrote:
On 8/10/07, Eric Niebler <eric@boost-consulting.com> 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 Consider it withdrawn.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 But now that its clear and your suggestion is withdrawn, is your objection to the time series library also withdrawn?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