Merged in enriquefernandezperdomo/gtsam/add_dcs_robust_kernel (pull request #180)

Add DCS robust kernel
release/4.3a0
Frank Dellaert 2015-08-21 13:41:31 -07:00
commit 9e71ad793b
3 changed files with 194 additions and 4 deletions

View File

@ -696,7 +696,7 @@ Huber::Huber(double k, const ReweightScheme reweight)
}
double Huber::weight(double error) const {
return (error < k_) ? (1.0) : (k_ / fabs(error));
return (fabs(error) > k_) ? k_ / fabs(error) : 1.0;
}
void Huber::print(const std::string &s="") const {
@ -799,6 +799,66 @@ Welsh::shared_ptr Welsh::Create(double c, const ReweightScheme reweight) {
return shared_ptr(new Welsh(c, reweight));
}
/* ************************************************************************* */
// GemanMcClure
/* ************************************************************************* */
GemanMcClure::GemanMcClure(double c, const ReweightScheme reweight)
: Base(reweight), c_(c) {
}
double GemanMcClure::weight(double error) const {
const double c2 = c_*c_;
const double c4 = c2*c2;
const double c2error = c2 + error*error;
return c4/(c2error*c2error);
}
void GemanMcClure::print(const std::string &s="") const {
std::cout << s << ": Geman-McClure (" << c_ << ")" << std::endl;
}
bool GemanMcClure::equals(const Base &expected, double tol) const {
const GemanMcClure* p = dynamic_cast<const GemanMcClure*>(&expected);
if (p == NULL) return false;
return fabs(c_ - p->c_) < tol;
}
GemanMcClure::shared_ptr GemanMcClure::Create(double c, const ReweightScheme reweight) {
return shared_ptr(new GemanMcClure(c, reweight));
}
/* ************************************************************************* */
// DCS
/* ************************************************************************* */
DCS::DCS(double c, const ReweightScheme reweight)
: Base(reweight), c_(c) {
}
double DCS::weight(double error) const {
const double e2 = error*error;
if (e2 > c_)
{
const double w = 2.0*c_/(c_ + e2);
return w*w;
}
return 1.0;
}
void DCS::print(const std::string &s="") const {
std::cout << s << ": DCS (" << c_ << ")" << std::endl;
}
bool DCS::equals(const Base &expected, double tol) const {
const DCS* p = dynamic_cast<const DCS*>(&expected);
if (p == NULL) return false;
return fabs(c_ - p->c_) < tol;
}
DCS::shared_ptr DCS::Create(double c, const ReweightScheme reweight) {
return shared_ptr(new DCS(c, reweight));
}
} // namespace mEstimator
/* ************************************************************************* */

View File

@ -823,6 +823,65 @@ namespace gtsam {
}
};
/// GemanMcClure implements the "Geman-McClure" robust error model
/// (Zhang97ivc).
///
/// Note that Geman-McClure weight function uses the parameter c == 1.0,
/// but here it's allowed to use different values, so we actually have
/// the generalized Geman-McClure from (Agarwal15phd).
class GTSAM_EXPORT GemanMcClure : public Base {
public:
typedef boost::shared_ptr<GemanMcClure> shared_ptr;
GemanMcClure(double c = 1.0, const ReweightScheme reweight = Block);
virtual ~GemanMcClure() {}
virtual double weight(double error) const;
virtual void print(const std::string &s) const;
virtual bool equals(const Base& expected, double tol=1e-8) const;
static shared_ptr Create(double k, const ReweightScheme reweight = Block) ;
protected:
double c_;
private:
/** Serialization function */
friend class boost::serialization::access;
template<class ARCHIVE>
void serialize(ARCHIVE & ar, const unsigned int /*version*/) {
ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base);
ar & BOOST_SERIALIZATION_NVP(c_);
}
};
/// DCS implements the Dynamic Covariance Scaling robust error model
/// from the paper Robust Map Optimization (Agarwal13icra).
///
/// Under the special condition of the parameter c == 1.0 and not
/// forcing the output weight s <= 1.0, DCS is similar to Geman-McClure.
class GTSAM_EXPORT DCS : public Base {
public:
typedef boost::shared_ptr<DCS> shared_ptr;
DCS(double c = 1.0, const ReweightScheme reweight = Block);
virtual ~DCS() {}
virtual double weight(double error) const;
virtual void print(const std::string &s) const;
virtual bool equals(const Base& expected, double tol=1e-8) const;
static shared_ptr Create(double k, const ReweightScheme reweight = Block) ;
protected:
double c_;
private:
/** Serialization function */
friend class boost::serialization::access;
template<class ARCHIVE>
void serialize(ARCHIVE & ar, const unsigned int /*version*/) {
ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base);
ar & BOOST_SERIALIZATION_NVP(c_);
}
};
} ///\namespace mEstimator
/// Base class for robust error models

View File

@ -322,7 +322,7 @@ TEST(NoiseModel, WhitenInPlace)
}
/* ************************************************************************* */
TEST(NoiseModel, robustFunction)
TEST(NoiseModel, robustFunctionHuber)
{
const double k = 5.0, error1 = 1.0, error2 = 10.0;
const mEstimator::Huber::shared_ptr huber = mEstimator::Huber::Create(k);
@ -332,8 +332,28 @@ TEST(NoiseModel, robustFunction)
DOUBLES_EQUAL(0.5, weight2, 1e-8);
}
TEST(NoiseModel, robustFunctionGemanMcClure)
{
const double k = 1.0, error1 = 1.0, error2 = 10.0;
const mEstimator::GemanMcClure::shared_ptr gmc = mEstimator::GemanMcClure::Create(k);
const double weight1 = gmc->weight(error1),
weight2 = gmc->weight(error2);
DOUBLES_EQUAL(0.25 , weight1, 1e-8);
DOUBLES_EQUAL(9.80296e-5, weight2, 1e-8);
}
TEST(NoiseModel, robustFunctionDCS)
{
const double k = 1.0, error1 = 1.0, error2 = 10.0;
const mEstimator::DCS::shared_ptr dcs = mEstimator::DCS::Create(k);
const double weight1 = dcs->weight(error1),
weight2 = dcs->weight(error2);
DOUBLES_EQUAL(1.0 , weight1, 1e-8);
DOUBLES_EQUAL(0.00039211, weight2, 1e-8);
}
/* ************************************************************************* */
TEST(NoiseModel, robustNoise)
TEST(NoiseModel, robustNoiseHuber)
{
const double k = 10.0, error1 = 1.0, error2 = 100.0;
Matrix A = (Matrix(2, 2) << 1.0, 10.0, 100.0, 1000.0).finished();
@ -353,6 +373,57 @@ TEST(NoiseModel, robustNoise)
DOUBLES_EQUAL(sqrt(k/100.0)*1000.0, A(1,1), 1e-8);
}
TEST(NoiseModel, robustNoiseGemanMcClure)
{
const double k = 1.0, error1 = 1.0, error2 = 100.0;
const double a00 = 1.0, a01 = 10.0, a10 = 100.0, a11 = 1000.0;
Matrix A = (Matrix(2, 2) << a00, a01, a10, a11).finished();
Vector b = Vector2(error1, error2);
const Robust::shared_ptr robust = Robust::Create(
mEstimator::GemanMcClure::Create(k, mEstimator::GemanMcClure::Scalar),
Unit::Create(2));
robust->WhitenSystem(A, b);
const double k2 = k*k;
const double k4 = k2*k2;
const double k2error = k2 + error2*error2;
const double sqrt_weight_error1 = sqrt(0.25);
const double sqrt_weight_error2 = sqrt(k4/(k2error*k2error));
DOUBLES_EQUAL(sqrt_weight_error1*error1, b(0), 1e-8);
DOUBLES_EQUAL(sqrt_weight_error2*error2, b(1), 1e-8);
DOUBLES_EQUAL(sqrt_weight_error1*a00, A(0,0), 1e-8);
DOUBLES_EQUAL(sqrt_weight_error1*a01, A(0,1), 1e-8);
DOUBLES_EQUAL(sqrt_weight_error2*a10, A(1,0), 1e-8);
DOUBLES_EQUAL(sqrt_weight_error2*a11, A(1,1), 1e-8);
}
TEST(NoiseModel, robustNoiseDCS)
{
const double k = 1.0, error1 = 1.0, error2 = 100.0;
const double a00 = 1.0, a01 = 10.0, a10 = 100.0, a11 = 1000.0;
Matrix A = (Matrix(2, 2) << a00, a01, a10, a11).finished();
Vector b = Vector2(error1, error2);
const Robust::shared_ptr robust = Robust::Create(
mEstimator::DCS::Create(k, mEstimator::DCS::Scalar),
Unit::Create(2));
robust->WhitenSystem(A, b);
const double sqrt_weight = 2.0*k/(k + error2*error2);
DOUBLES_EQUAL(error1, b(0), 1e-8);
DOUBLES_EQUAL(sqrt_weight*error2, b(1), 1e-8);
DOUBLES_EQUAL(a00, A(0,0), 1e-8);
DOUBLES_EQUAL(a01, A(0,1), 1e-8);
DOUBLES_EQUAL(sqrt_weight*a10, A(1,0), 1e-8);
DOUBLES_EQUAL(sqrt_weight*a11, A(1,1), 1e-8);
}
/* ************************************************************************* */
#define TEST_GAUSSIAN(gaussian)\
EQUALITY(info, gaussian->information());\