gistfile1.cpp

#include <iostream>
#include <shogun/base/init.h>
#include <shogun/lib/SGVector.h>
#include <Eigen/Eigen>
 
using namespace shogun;
using namespace std;
using namespace Eigen;
 
template <class Vector>
struct type_traits
{
	typedef typename Vector::Scalar value_type;
};
 
template <class Vector, typename T, typename... Other>
struct dot_impl;
 
template <class T, typename... Other>
struct dot_impl<SGVector<T>, T, Other...>
{
	static T compute(SGVector<T> a, SGVector<T> b)
	{
		typedef Matrix<T, Dynamic, 1> VectorXt;
		Map<VectorXt> av(a.vector, a.vlen);
		Map<VectorXt> bv(b.vector, b.vlen);
		return av.dot(bv);
	}
};
 
template <class T, typename... Other>
struct dot_impl<Matrix<T,Other...>,T, Other...>
{
	static T compute(Matrix<T,Other...> a, Matrix<T,Other...> b)
	{
		return a.dot(b);
	}
};
 
namespace linalg
{
 
template <template class Vector, typename... Other>
typename type_traits<Vector>::value_type dot(Vector a, Vector b)
{
	return dot_impl<Vector,type_traits<Vector>::value_type,Other...>::compute(a, b);
}
 
}
 
int main()
{
	init_shogun_with_defaults();
	SGVector<float64_t> a(10);
	a.set_const(10);
	cout << linalg::dot(a, a) << endl;
	VectorXf b(10);
	b=VectorXf::Random(10);
	cout << linalg::dot(b, b) << endl;
	Vector3d c=Vector3d::Random();
	cout << linalg::dot(c, c) << endl;
	SGVector<int64_t> d(10);
	d.set_const(10);
	cout << linalg::dot(d, d) << endl;
	exit_shogun();
	return 0;
}