Re: [boost] [Review] Review of the Accumulators library beginstoday Jan 29

From: John Maddock (john_at_[hidden])
Date: 2007-01-31 04:23:00

Matthias Troyer wrote:
>> This would be particularly useful for parallel computing
>> applications.
>>
>> Is this possible? Would it be difficult to add?

I agree that this would be highly desirable.

> Yes, this is definitely needed but I think it will be lots of work to
> add it, based on my own experience in implementing something like
> this in our ALPS library for parallel Monte Carlo simulations. I am
> planning to think about this sometime this year, but believe it is a
> substantial extension to the library and will not be easy to design
> right. The problem I see is that preparing an estimate from a
> sequence of values, and preparing an estimate from a number of
> estimates of independent accumulators requires different algorithms.,
> e.g.:

Right: and for some accumulators the addition of two accumulators may not be 
possible at all.  But can't we make this a conceptual requirement that if 
you try and combine two accumulator sets, then each accumulator must have a 
"combine" method (otherwise you get a compile time error).  The "combine" 
methods for min/max/sum/count etc are all trivial aren't they - and could be 
added fairly easily ?  But Eric would know the details :-)

John.