Using Boost Accumulators with Eigen::Vector types

Question

I am having some problems combining Eigen::VectorXd types with the Boost accumulator library:

#include <iostream>
#include <Eigen/Core>
#include <boost/accumulators/accumulators.hpp>
#include <boost/accumulators/statistics/stats.hpp>
#include <boost/accumulators/statistics/mean.hpp>

using namespace boost::accumulators;
using namespace Eigen;

int main()
{
   Vector2f a(1.0, 2.0), b(3.0, 10.0);

   accumulator_set<Vector2f, stats<tag::mean> > acc(Vector2f::Zero());

   acc(a);
   acc(b);

   std::cout << mean(acc) << std::endl;
   std::cout << ((a+b)/2.0) << std::endl;

   return 0;
}

On my system this produces:

4.41629e-39
0
2
6

So while direct computation is fine (Eigen vectors support all of the usual numerical operators) Boost accumulators fail at runtime without an error.

Answer 1

User defined type need specialize std::numeric_limits. see https://svn.boost.org/trac/boost/ticket/5491