target.hpp

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#ifndef TARGET_HPP
#define TARGET_HPP
 
#include <armadillo>
 
#include <visualization_msgs/MarkerArray.h>
 
#include <ergodic_exploration/grid.hpp>
#include <ergodic_exploration/numerics.hpp>
 
namespace ergodic_exploration
{
using arma::mat;
using arma::vec;
struct Gaussian;
typedef std::vector<Gaussian> GaussianList;
 
struct Gaussian
{
  Gaussian()
  {
  }
 
  Gaussian(const vec& mu, const vec& sigmas)
    : mu(mu), cov(arma::diagmat(square(sigmas))), cov_inv(inv(cov))
  {
  }
 
  double operator()(const vec& pt) const
  {
    const vec diff = pt - mu;
    return std::exp(-0.5 * dot(diff.t() * cov_inv, diff));
  }
 
  double operator()(const vec& pt, const vec& trans) const
  {
    // DEBUG
    // if (any(mu - trans) < 0.0)
    // {
    //   std::cout << "WARNING: Targert mean not within fourier domain" << std::endl;
    // }
 
    // translate mu into frame of fourier domain
    const vec diff = pt - (mu - trans);
    return std::exp(-0.5 * dot(diff.t() * cov_inv, diff));
  }
 
  vec mu;       // mean
  mat cov;      // covariance
  mat cov_inv;  // inverse of covariance
};
 
class Target
{
public:
  Target();
 
  Target(const GaussianList& gaussians);
 
  void addGaussian(const Gaussian& g);
 
  void deleteGaussian(unsigned int idx);
 
  double evaluate(const vec& pt, const vec& trans) const;
 
  vec fill(const vec& trans, const mat& phi_grid) const;
 
  visualization_msgs::MarkerArray markers(const std::string& frame) const;
 
private:
  GaussianList gaussians_;  // list of target gaussians
};
}  // namespace ergodic_exploration
#endif