Re: [boost] [Accumulators] Passing construction arguments to dependent statistics

From: Hugo Duncan (hugoduncan_at_[hidden])
Date: 2007-08-01 15:11:32

>>> The resulting argument pack is passed as the constructor parameter to
>>> all the accumulators in the set. Your accumulator can then extract the
>>> coefficients argument from the pack with "args[coefficients]".
>>
>> My filter depends on the delay buffer I have defined which has the
>> cache_size constructor argument.  Since I am specifying the list of
>> coefficients, I want the cache_size to be set to the number of elements  
>> in
>> my coefficient list, with out having to specify it, ie without having to
>> write:
>>
>>     array<double,5> coeffs={0.1,0.2,0.1};
>>     accumulator_set<... > acc( .., coefficients = coeffs,  
>> cache_size=5...);
>>
>
> Let me see if I understand. You want the delay buffer to use the
> cache_size parameter if it is specified, and if not, check to see if the
> coefficients parameter is specified, and if so, use the size of the
> coefficients array. This is possible.

[cut proposed solution]

Thanks Eric, that would probably work (as long as I define the  
coefficients named paramter seperately from the filter or the delay).

Ideally, though,  I was looking for a solution that allowed me to reuse  
the delay buffer without modifying it.  That way it could be used as a  
lower layer for any algorithm that needed recent time history.  Maybe I am  
being over ambitious...