Re: [Boost-users] Statistical Accumulator

Subject: Re: [Boost-users] Statistical Accumulator
From: Eric Niebler (eric_at_[hidden])
Date: 2010-07-07 08:00:23

On 7/6/2010 4:31 PM, Kraus Philipp wrote:
> Hi,
> 
> I try to calulate the covariance from some data.
> 
>  http://www.boost.org/doc/libs/1_43_0/doc/html/accumulators/user_s_guide.html#accumulators.user_s_guide.the_statistical_accumulators_library.covariance
> 
> I don't understand the call "acc call". I would like to rebuild the cov
> command form Matlab for matrix data
> (http://www.mathworks.com/access/helpdesk/help/techdoc/ref/cov.html).
> If this is correct, when I give as the first argument of command data
> from the first line and second as the  data of the first column to the
> first value to calculate the new matrix?
> 
> I try try compile the excample, but I get a compiler error on the
> "acc::tag::covariate1":
> 
>     acc::accumulator_set<double, acc::stats<acc::tag::covariance<double,
> acc::tag::covariate1> > > xx;
> 
>     xx(1., acc::tag::covariate1 = 2.);
>     xx(1., acc::tag::covariate1 = 4.);
>     xx(2., acc::tag::covariate1 = 3.);
>     xx(6., acc::tag::covariate1 = 1.);
> 
>     std::cout << acc::covariance(xx) << std::endl;
> 
> The error text: "expected primary-expression befor = token". Sorry, it's
> a little bit late, so I don't see my mistake

It's impossible to say from just the little code fragment you've
included here. Have you #include
<boost/accumulators/statistics/covariance.hpp>?

Please include a complete example that demonstrates the problem next time.

Thanks,

-- 
Eric Niebler
BoostPro Computing
http://www.boostpro.com