/*
 * tensorInterface.cpp
 * @brief Interfacing tensors template library and gtsam
 * Created on: Feb 12, 2010
 * @author: Frank Dellaert
 */

#include <gtsam/geometry/tensorInterface.h>

using namespace std;
using namespace tensors;

namespace gtsam {

boost::tuple<int, double, Vector> DLT(const Matrix& A) {

	// Do SVD on A
	Matrix U, V;
	Vector S;
	svd(A, U, S, V, false);

	// Find minimum column
	int n = V.size2(), min_j = n - 1, rank = 0;
	for (int j = 0; j < n; j++)
		if (S(j) > 1e-9)
			rank++;
	double min_S = S(min_j);
	for (int j = 0; j < n - 1; j++)
		if (S(j) < min_S) {
			min_j = j;
			min_S = S(j);
		}

	// Return minimum column
	return boost::tuple<int, double, Vector>(rank, min_S, column_(V, min_j));
}

} // namespace gtsam