Merge pull request #1091 from borglab/feature/linear_samplers

release/4.3a0
Frank Dellaert 2022-02-08 00:10:50 -05:00 committed by GitHub
commit c34456268a
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13 changed files with 408 additions and 99 deletions

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@ -26,6 +26,9 @@
using namespace std;
using namespace gtsam;
// In Wrappers we have no access to this so have a default ready
static std::mt19937_64 kRandomNumberGenerator(42);
namespace gtsam {
// Instantiate base class
@ -37,28 +40,50 @@ namespace gtsam {
return Base::equals(bn, tol);
}
/* ************************************************************************* */
VectorValues GaussianBayesNet::optimize() const
{
VectorValues soln; // no missing variables -> just create an empty vector
return optimize(soln);
/* ************************************************************************ */
VectorValues GaussianBayesNet::optimize() const {
VectorValues solution; // no missing variables -> create an empty vector
return optimize(solution);
}
/* ************************************************************************* */
VectorValues GaussianBayesNet::optimize(
const VectorValues& solutionForMissing) const {
VectorValues soln(solutionForMissing); // possibly empty
VectorValues GaussianBayesNet::optimize(VectorValues solution) const {
// (R*x)./sigmas = y by solving x=inv(R)*(y.*sigmas)
/** solve each node in turn in topological sort order (parents first)*/
for (auto cg: boost::adaptors::reverse(*this)) {
// solve each node in reverse topological sort order (parents first)
for (auto cg : boost::adaptors::reverse(*this)) {
// i^th part of R*x=y, x=inv(R)*y
// (Rii*xi + R_i*x(i+1:))./si = yi <-> xi = inv(Rii)*(yi.*si - R_i*x(i+1:))
soln.insert(cg->solve(soln));
// (Rii*xi + R_i*x(i+1:))./si = yi =>
// xi = inv(Rii)*(yi.*si - R_i*x(i+1:))
solution.insert(cg->solve(solution));
}
return soln;
return solution;
}
/* ************************************************************************* */
/* ************************************************************************ */
VectorValues GaussianBayesNet::sample(std::mt19937_64* rng) const {
VectorValues result; // no missing variables -> create an empty vector
return sample(result, rng);
}
VectorValues GaussianBayesNet::sample(VectorValues result,
std::mt19937_64* rng) const {
// sample each node in reverse topological sort order (parents first)
for (auto cg : boost::adaptors::reverse(*this)) {
const VectorValues sampled = cg->sample(result, rng);
result.insert(sampled);
}
return result;
}
/* ************************************************************************ */
VectorValues GaussianBayesNet::sample() const {
return sample(&kRandomNumberGenerator);
}
VectorValues GaussianBayesNet::sample(VectorValues given) const {
return sample(given, &kRandomNumberGenerator);
}
/* ************************************************************************ */
VectorValues GaussianBayesNet::optimizeGradientSearch() const
{
gttic(GaussianBayesTree_optimizeGradientSearch);

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@ -88,11 +88,35 @@ namespace gtsam {
/// @name Standard Interface
/// @{
/// Solve the GaussianBayesNet, i.e. return \f$ x = R^{-1}*d \f$, by back-substitution
/// Solve the GaussianBayesNet, i.e. return \f$ x = R^{-1}*d \f$, by
/// back-substitution
VectorValues optimize() const;
/// Version of optimize for incomplete BayesNet, needs solution for missing variables
VectorValues optimize(const VectorValues& solutionForMissing) const;
/// Version of optimize for incomplete BayesNet, given missing variables
VectorValues optimize(const VectorValues given) const;
/**
* Sample using ancestral sampling
* Example:
* std::mt19937_64 rng(42);
* auto sample = gbn.sample(&rng);
*/
VectorValues sample(std::mt19937_64* rng) const;
/**
* Sample from an incomplete BayesNet, given missing variables
* Example:
* std::mt19937_64 rng(42);
* VectorValues given = ...;
* auto sample = gbn.sample(given, &rng);
*/
VectorValues sample(VectorValues given, std::mt19937_64* rng) const;
/// Sample using ancestral sampling, use default rng
VectorValues sample() const;
/// Sample from an incomplete BayesNet, use default rng
VectorValues sample(VectorValues given) const;
/**
* Return ordering corresponding to a topological sort.

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@ -18,6 +18,7 @@
#include <gtsam/linear/linearExceptions.h>
#include <gtsam/linear/GaussianConditional.h>
#include <gtsam/linear/VectorValues.h>
#include <gtsam/linear/Sampler.h>
#include <boost/format.hpp>
#ifdef __GNUC__
@ -34,6 +35,9 @@
#include <list>
#include <string>
// In Wrappers we have no access to this so have a default ready
static std::mt19937_64 kRandomNumberGenerator(42);
using namespace std;
namespace gtsam {
@ -43,19 +47,47 @@ namespace gtsam {
Key key, const Vector& d, const Matrix& R, const SharedDiagonal& sigmas) :
BaseFactor(key, R, d, sigmas), BaseConditional(1) {}
/* ************************************************************************* */
GaussianConditional::GaussianConditional(
Key key, const Vector& d, const Matrix& R,
Key name1, const Matrix& S, const SharedDiagonal& sigmas) :
BaseFactor(key, R, name1, S, d, sigmas), BaseConditional(1) {}
/* ************************************************************************ */
GaussianConditional::GaussianConditional(Key key, const Vector& d,
const Matrix& R, Key parent1,
const Matrix& S,
const SharedDiagonal& sigmas)
: BaseFactor(key, R, parent1, S, d, sigmas), BaseConditional(1) {}
/* ************************************************************************* */
GaussianConditional::GaussianConditional(
Key key, const Vector& d, const Matrix& R,
Key name1, const Matrix& S, Key name2, const Matrix& T, const SharedDiagonal& sigmas) :
BaseFactor(key, R, name1, S, name2, T, d, sigmas), BaseConditional(1) {}
/* ************************************************************************ */
GaussianConditional::GaussianConditional(Key key, const Vector& d,
const Matrix& R, Key parent1,
const Matrix& S, Key parent2,
const Matrix& T,
const SharedDiagonal& sigmas)
: BaseFactor(key, R, parent1, S, parent2, T, d, sigmas),
BaseConditional(1) {}
/* ************************************************************************* */
/* ************************************************************************ */
GaussianConditional GaussianConditional::FromMeanAndStddev(
Key key, const Matrix& A, Key parent, const Vector& b, double sigma) {
// |Rx + Sy - d| = |x-(Ay + b)|/sigma
const Matrix R = Matrix::Identity(b.size(), b.size());
const Matrix S = -A;
const Vector d = b;
return GaussianConditional(key, d, R, parent, S,
noiseModel::Isotropic::Sigma(b.size(), sigma));
}
/* ************************************************************************ */
GaussianConditional GaussianConditional::FromMeanAndStddev(
Key key, const Matrix& A1, Key parent1, const Matrix& A2, Key parent2,
const Vector& b, double sigma) {
// |Rx + Sy + Tz - d| = |x-(A1 y + A2 z + b)|/sigma
const Matrix R = Matrix::Identity(b.size(), b.size());
const Matrix S = -A1;
const Matrix T = -A2;
const Vector d = b;
return GaussianConditional(key, d, R, parent1, S, parent2, T,
noiseModel::Isotropic::Sigma(b.size(), sigma));
}
/* ************************************************************************ */
void GaussianConditional::print(const string &s, const KeyFormatter& formatter) const {
cout << s << " Conditional density ";
for (const_iterator it = beginFrontals(); it != endFrontals(); ++it) {
@ -192,7 +224,44 @@ namespace gtsam {
}
}
/* ************************************************************************* */
/* ************************************************************************ */
VectorValues GaussianConditional::sample(const VectorValues& parentsValues,
std::mt19937_64* rng) const {
if (nrFrontals() != 1) {
throw std::invalid_argument(
"GaussianConditional::sample can only be called on single variable "
"conditionals");
}
if (!model_) {
throw std::invalid_argument(
"GaussianConditional::sample can only be called if a diagonal noise "
"model was specified at construction.");
}
VectorValues solution = solve(parentsValues);
Key key = firstFrontalKey();
const Vector& sigmas = model_->sigmas();
solution[key] += Sampler::sampleDiagonal(sigmas, rng);
return solution;
}
VectorValues GaussianConditional::sample(std::mt19937_64* rng) const {
if (nrParents() != 0)
throw std::invalid_argument(
"sample() can only be invoked on no-parent prior");
VectorValues values;
return sample(values);
}
/* ************************************************************************ */
VectorValues GaussianConditional::sample() const {
return sample(&kRandomNumberGenerator);
}
VectorValues GaussianConditional::sample(const VectorValues& given) const {
return sample(given, &kRandomNumberGenerator);
}
/* ************************************************************************ */
#ifdef GTSAM_ALLOW_DEPRECATED_SINCE_V42
void GTSAM_DEPRECATED
GaussianConditional::scaleFrontalsBySigma(VectorValues& gy) const {

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@ -26,12 +26,15 @@
#include <gtsam/inference/Conditional.h>
#include <gtsam/linear/VectorValues.h>
#include <random> // for std::mt19937_64
namespace gtsam {
/**
* A conditional Gaussian functions as the node in a Bayes network
* A GaussianConditional functions as the node in a Bayes network.
* It has a set of parents y,z, etc. and implements a probability density on x.
* The negative log-probability is given by \f$ \frac{1}{2} |Rx - (d - Sy - Tz - ...)|^2 \f$
* @addtogroup linear
*/
class GTSAM_EXPORT GaussianConditional :
public JacobianFactor,
@ -43,6 +46,9 @@ namespace gtsam {
typedef JacobianFactor BaseFactor; ///< Typedef to our factor base class
typedef Conditional<BaseFactor, This> BaseConditional; ///< Typedef to our conditional base class
/// @name Constructors
/// @{
/** default constructor needed for serialization */
GaussianConditional() {}
@ -51,13 +57,14 @@ namespace gtsam {
const SharedDiagonal& sigmas = SharedDiagonal());
/** constructor with only one parent |Rx+Sy-d| */
GaussianConditional(Key key, const Vector& d, const Matrix& R,
Key name1, const Matrix& S, const SharedDiagonal& sigmas = SharedDiagonal());
GaussianConditional(Key key, const Vector& d, const Matrix& R, Key parent1,
const Matrix& S,
const SharedDiagonal& sigmas = SharedDiagonal());
/** constructor with two parents |Rx+Sy+Tz-d| */
GaussianConditional(Key key, const Vector& d, const Matrix& R,
Key name1, const Matrix& S, Key name2, const Matrix& T,
const SharedDiagonal& sigmas = SharedDiagonal());
GaussianConditional(Key key, const Vector& d, const Matrix& R, Key parent1,
const Matrix& S, Key parent2, const Matrix& T,
const SharedDiagonal& sigmas = SharedDiagonal());
/** Constructor with arbitrary number of frontals and parents.
* @tparam TERMS A container whose value type is std::pair<Key, Matrix>, specifying the
@ -76,6 +83,17 @@ namespace gtsam {
const KEYS& keys, size_t nrFrontals, const VerticalBlockMatrix& augmentedMatrix,
const SharedDiagonal& sigmas = SharedDiagonal());
/// Construct from mean A1 p1 + b and standard deviation.
static GaussianConditional FromMeanAndStddev(Key key, const Matrix& A,
Key parent, const Vector& b,
double sigma);
/// Construct from mean A1 p1 + A2 p2 + b and standard deviation.
static GaussianConditional FromMeanAndStddev(Key key, //
const Matrix& A1, Key parent1,
const Matrix& A2, Key parent2,
const Vector& b, double sigma);
/** Combine several GaussianConditional into a single dense GC. The conditionals enumerated by
* \c first and \c last must be in increasing order, meaning that the parents of any
* conditional may not include a conditional coming before it.
@ -86,6 +104,10 @@ namespace gtsam {
template<typename ITERATOR>
static shared_ptr Combine(ITERATOR firstConditional, ITERATOR lastConditional);
/// @}
/// @name Testable
/// @{
/** print */
void print(const std::string& = "GaussianConditional",
const KeyFormatter& formatter = DefaultKeyFormatter) const override;
@ -93,6 +115,10 @@ namespace gtsam {
/** equals function */
bool equals(const GaussianFactor&cg, double tol = 1e-9) const override;
/// @}
/// @name Standard Interface
/// @{
/** Return a view of the upper-triangular R block of the conditional */
constABlock R() const { return Ab_.range(0, nrFrontals()); }
@ -125,10 +151,39 @@ namespace gtsam {
/** Performs transpose backsubstition in place on values */
void solveTransposeInPlace(VectorValues& gy) const;
/**
* Sample from conditional, zero parent version
* Example:
* std::mt19937_64 rng(42);
* auto sample = gbn.sample(&rng);
*/
VectorValues sample(std::mt19937_64* rng) const;
/**
* Sample from conditional, given missing variables
* Example:
* std::mt19937_64 rng(42);
* VectorValues given = ...;
* auto sample = gbn.sample(given, &rng);
*/
VectorValues sample(const VectorValues& parentsValues,
std::mt19937_64* rng) const;
/// Sample, use default rng
VectorValues sample() const;
/// Sample with given values, use default rng
VectorValues sample(const VectorValues& parentsValues) const;
/// @}
#ifdef GTSAM_ALLOW_DEPRECATED_SINCE_V42
/// @name Deprecated
/// @{
/** Scale the values in \c gy according to the sigmas for the frontal variables in this
* conditional. */
void GTSAM_DEPRECATED scaleFrontalsBySigma(VectorValues& gy) const;
/// @}
#endif
private:

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@ -23,9 +23,12 @@ using namespace std;
namespace gtsam {
/* ************************************************************************* */
GaussianDensity GaussianDensity::FromMeanAndStddev(Key key, const Vector& mean, const double& sigma)
{
return GaussianDensity(key, mean / sigma, Matrix::Identity(mean.size(), mean.size()) / sigma);
GaussianDensity GaussianDensity::FromMeanAndStddev(Key key,
const Vector& mean,
double sigma) {
return GaussianDensity(key, mean,
Matrix::Identity(mean.size(), mean.size()),
noiseModel::Isotropic::Sigma(mean.size(), sigma));
}
/* ************************************************************************* */
@ -35,8 +38,8 @@ namespace gtsam {
for(const_iterator it = beginFrontals(); it != endFrontals(); ++it)
cout << (boost::format("[%1%]")%(formatter(*it))).str() << " ";
cout << endl;
gtsam::print(Matrix(R()), "R: ");
gtsam::print(Vector(d()), "d: ");
gtsam::print(mean(), "mean: ");
gtsam::print(covariance(), "covariance: ");
if(model_)
model_->print("Noise model: ");
}

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@ -24,11 +24,10 @@
namespace gtsam {
/**
* A Gaussian density.
*
* It is implemented as a GaussianConditional without parents.
* A GaussianDensity is a GaussianConditional without parents.
* The negative log-probability is given by \f$ |Rx - d|^2 \f$
* with \f$ \Lambda = \Sigma^{-1} = R^T R \f$ and \f$ \mu = R^{-1} d \f$
* @addtogroup linear
*/
class GTSAM_EXPORT GaussianDensity : public GaussianConditional {
@ -52,8 +51,9 @@ namespace gtsam {
GaussianDensity(Key key, const Vector& d, const Matrix& R, const SharedDiagonal& noiseModel = SharedDiagonal()) :
GaussianConditional(key, d, R, noiseModel) {}
/// Construct using a mean and variance
static GaussianDensity FromMeanAndStddev(Key key, const Vector& mean, const double& sigma);
/// Construct using a mean and standard deviation
static GaussianDensity FromMeanAndStddev(Key key, const Vector& mean,
double sigma);
/// print
void print(const std::string& = "GaussianDensity",

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@ -22,14 +22,18 @@ namespace gtsam {
/* ************************************************************************* */
Sampler::Sampler(const noiseModel::Diagonal::shared_ptr& model,
uint_fast64_t seed)
: model_(model), generator_(seed) {}
: model_(model), generator_(seed) {
if (!model) {
throw std::invalid_argument("Sampler::Sampler needs a non-null model.");
}
}
/* ************************************************************************* */
Sampler::Sampler(const Vector& sigmas, uint_fast64_t seed)
: model_(noiseModel::Diagonal::Sigmas(sigmas, true)), generator_(seed) {}
/* ************************************************************************* */
Vector Sampler::sampleDiagonal(const Vector& sigmas) const {
Vector Sampler::sampleDiagonal(const Vector& sigmas, std::mt19937_64* rng) {
size_t d = sigmas.size();
Vector result(d);
for (size_t i = 0; i < d; i++) {
@ -39,14 +43,18 @@ Vector Sampler::sampleDiagonal(const Vector& sigmas) const {
if (sigma == 0.0) {
result(i) = 0.0;
} else {
typedef std::normal_distribution<double> Normal;
Normal dist(0.0, sigma);
result(i) = dist(generator_);
std::normal_distribution<double> dist(0.0, sigma);
result(i) = dist(*rng);
}
}
return result;
}
/* ************************************************************************* */
Vector Sampler::sampleDiagonal(const Vector& sigmas) const {
return sampleDiagonal(sigmas, &generator_);
}
/* ************************************************************************* */
Vector Sampler::sample() const {
assert(model_.get());

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@ -63,15 +63,9 @@ class GTSAM_EXPORT Sampler {
/// @name access functions
/// @{
size_t dim() const {
assert(model_.get());
return model_->dim();
}
size_t dim() const { return model_->dim(); }
Vector sigmas() const {
assert(model_.get());
return model_->sigmas();
}
Vector sigmas() const { return model_->sigmas(); }
const noiseModel::Diagonal::shared_ptr& model() const { return model_; }
@ -82,6 +76,8 @@ class GTSAM_EXPORT Sampler {
/// sample from distribution
Vector sample() const;
/// sample with given random number generator
static Vector sampleDiagonal(const Vector& sigmas, std::mt19937_64* rng);
/// @}
protected:

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@ -468,15 +468,33 @@ virtual class GaussianConditional : gtsam::JacobianFactor {
GaussianConditional(size_t key, Vector d, Matrix R, size_t name1, Matrix S,
size_t name2, Matrix T);
// Standard Interface
// Named constructors
static gtsam::GaussianConditional FromMeanAndStddev(gtsam::Key key,
const Matrix& A,
gtsam::Key parent,
const Vector& b,
double sigma);
static gtsam::GaussianConditional FromMeanAndStddev(gtsam::Key key,
const Matrix& A1,
gtsam::Key parent1,
const Matrix& A2,
gtsam::Key parent2,
const Vector& b,
double sigma);
// Testable
void print(string s = "GaussianConditional",
const gtsam::KeyFormatter& keyFormatter =
gtsam::DefaultKeyFormatter) const;
bool equals(const gtsam::GaussianConditional& cg, double tol) const;
// Standard Interface
gtsam::Key firstFrontalKey() const;
gtsam::VectorValues solve(const gtsam::VectorValues& parents) const;
gtsam::VectorValues sample(const gtsam::VectorValues& parents) const;
gtsam::VectorValues sample() const;
// Advanced Interface
gtsam::VectorValues solve(const gtsam::VectorValues& parents) const;
gtsam::VectorValues solveOtherRHS(const gtsam::VectorValues& parents,
const gtsam::VectorValues& rhs) const;
void solveTransposeInPlace(gtsam::VectorValues& gy) const;
@ -490,14 +508,21 @@ virtual class GaussianConditional : gtsam::JacobianFactor {
#include <gtsam/linear/GaussianDensity.h>
virtual class GaussianDensity : gtsam::GaussianConditional {
//Constructors
GaussianDensity(size_t key, Vector d, Matrix R, const gtsam::noiseModel::Diagonal* sigmas);
// Constructors
GaussianDensity(gtsam::Key key, Vector d, Matrix R,
const gtsam::noiseModel::Diagonal* sigmas);
//Standard Interface
static gtsam::GaussianDensity FromMeanAndStddev(gtsam::Key key,
const Vector& mean,
double sigma);
// Testable
void print(string s = "GaussianDensity",
const gtsam::KeyFormatter& keyFormatter =
gtsam::DefaultKeyFormatter) const;
bool equals(const gtsam::GaussianDensity &cg, double tol) const;
bool equals(const gtsam::GaussianDensity& cg, double tol) const;
// Standard Interface
Vector mean() const;
Matrix covariance() const;
};
@ -514,6 +539,21 @@ virtual class GaussianBayesNet {
bool equals(const gtsam::GaussianBayesNet& other, double tol) const;
size_t size() const;
// Standard interface
void push_back(gtsam::GaussianConditional* conditional);
void push_back(const gtsam::GaussianBayesNet& bayesNet);
gtsam::GaussianConditional* front() const;
gtsam::GaussianConditional* back() const;
gtsam::VectorValues optimize() const;
gtsam::VectorValues optimize(gtsam::VectorValues given) const;
gtsam::VectorValues optimizeGradientSearch() const;
gtsam::VectorValues sample(gtsam::VectorValues given) const;
gtsam::VectorValues sample() const;
gtsam::VectorValues backSubstitute(const gtsam::VectorValues& gx) const;
gtsam::VectorValues backSubstituteTranspose(const gtsam::VectorValues& gx) const;
// FactorGraph derived interface
gtsam::GaussianConditional* at(size_t idx) const;
gtsam::KeySet keys() const;
@ -522,22 +562,12 @@ virtual class GaussianBayesNet {
void saveGraph(const string& s) const;
gtsam::GaussianConditional* front() const;
gtsam::GaussianConditional* back() const;
void push_back(gtsam::GaussianConditional* conditional);
void push_back(const gtsam::GaussianBayesNet& bayesNet);
gtsam::VectorValues optimize() const;
gtsam::VectorValues optimize(gtsam::VectorValues& solutionForMissing) const;
std::pair<Matrix, Vector> matrix() const;
gtsam::VectorValues optimizeGradientSearch() const;
gtsam::VectorValues gradient(const gtsam::VectorValues& x0) const;
gtsam::VectorValues gradientAtZero() const;
double error(const gtsam::VectorValues& x) const;
double determinant() const;
double logDeterminant() const;
gtsam::VectorValues backSubstitute(const gtsam::VectorValues& gx) const;
gtsam::VectorValues backSubstituteTranspose(const gtsam::VectorValues& gx) const;
string dot(
const gtsam::KeyFormatter& keyFormatter = gtsam::DefaultKeyFormatter,

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@ -16,10 +16,12 @@
*/
#include <gtsam/linear/GaussianBayesNet.h>
#include <gtsam/linear/GaussianDensity.h>
#include <gtsam/linear/JacobianFactor.h>
#include <gtsam/linear/GaussianFactorGraph.h>
#include <gtsam/base/Testable.h>
#include <gtsam/base/numericalDerivative.h>
#include <gtsam/inference/Symbol.h>
#include <CppUnitLite/TestHarness.h>
#include <boost/tuple/tuple.hpp>
@ -35,6 +37,7 @@ using namespace boost::assign;
using namespace std::placeholders;
using namespace std;
using namespace gtsam;
using symbol_shorthand::X;
static const Key _x_ = 11, _y_ = 22, _z_ = 33;
@ -138,6 +141,30 @@ TEST( GaussianBayesNet, optimize3 )
EXPECT(assert_equal(expected, actual));
}
/* ************************************************************************* */
TEST(GaussianBayesNet, sample) {
GaussianBayesNet gbn;
Matrix A1 = (Matrix(2, 2) << 1., 2., 3., 4.).finished();
const Vector2 mean(20, 40), b(10, 10);
const double sigma = 0.01;
gbn.add(GaussianConditional::FromMeanAndStddev(X(0), A1, X(1), b, sigma));
gbn.add(GaussianDensity::FromMeanAndStddev(X(1), mean, sigma));
auto actual = gbn.sample();
EXPECT_LONGS_EQUAL(2, actual.size());
EXPECT(assert_equal(mean, actual[X(1)], 50 * sigma));
EXPECT(assert_equal(A1 * mean + b, actual[X(0)], 50 * sigma));
// Use a specific random generator
std::mt19937_64 rng(4242);
auto actual3 = gbn.sample(&rng);
EXPECT_LONGS_EQUAL(2, actual.size());
// regression is not repeatable across platforms/versions :-(
// EXPECT(assert_equal(Vector2(20.0129382, 40.0039798), actual[X(1)], 1e-5));
// EXPECT(assert_equal(Vector2(110.032083, 230.039811), actual[X(0)], 1e-5));
}
/* ************************************************************************* */
TEST(GaussianBayesNet, ordering)
{

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@ -20,9 +20,10 @@
#include <gtsam/base/Matrix.h>
#include <gtsam/base/VerticalBlockMatrix.h>
#include <gtsam/inference/Key.h>
#include <gtsam/inference/Symbol.h>
#include <gtsam/linear/JacobianFactor.h>
#include <gtsam/linear/GaussianConditional.h>
#include <gtsam/linear/GaussianDensity.h>
#include <gtsam/linear/GaussianBayesNet.h>
#include <boost/assign/std/list.hpp>
@ -38,6 +39,7 @@
using namespace gtsam;
using namespace std;
using namespace boost::assign;
using symbol_shorthand::X;
static const double tol = 1e-5;
@ -316,5 +318,60 @@ TEST( GaussianConditional, isGaussianFactor ) {
}
/* ************************************************************************* */
int main() { TestResult tr; return TestRegistry::runAllTests(tr);}
// Test FromMeanAndStddev named constructors
TEST(GaussianConditional, FromMeanAndStddev) {
Matrix A1 = (Matrix(2, 2) << 1., 2., 3., 4.).finished();
Matrix A2 = (Matrix(2, 2) << 5., 6., 7., 8.).finished();
const Vector2 b(20, 40), x0(1, 2), x1(3, 4), x2(5, 6);
const double sigma = 3;
VectorValues values = map_list_of(X(0), x0)(X(1), x1)(X(2), x2);
auto conditional1 =
GaussianConditional::FromMeanAndStddev(X(0), A1, X(1), b, sigma);
Vector2 e1 = (x0 - (A1 * x1 + b)) / sigma;
double expected1 = 0.5 * e1.dot(e1);
EXPECT_DOUBLES_EQUAL(expected1, conditional1.error(values), 1e-9);
auto conditional2 = GaussianConditional::FromMeanAndStddev(X(0), A1, X(1), A2,
X(2), b, sigma);
Vector2 e2 = (x0 - (A1 * x1 + A2 * x2 + b)) / sigma;
double expected2 = 0.5 * e2.dot(e2);
EXPECT_DOUBLES_EQUAL(expected2, conditional2.error(values), 1e-9);
}
/* ************************************************************************* */
// Test sampling
TEST(GaussianConditional, sample) {
Matrix A1 = (Matrix(2, 2) << 1., 2., 3., 4.).finished();
const Vector2 b(20, 40), x1(3, 4);
const double sigma = 0.01;
auto density = GaussianDensity::FromMeanAndStddev(X(0), b, sigma);
auto actual1 = density.sample();
EXPECT_LONGS_EQUAL(1, actual1.size());
EXPECT(assert_equal(b, actual1[X(0)], 50 * sigma));
VectorValues given;
given.insert(X(1), x1);
auto conditional =
GaussianConditional::FromMeanAndStddev(X(0), A1, X(1), b, sigma);
auto actual2 = conditional.sample(given);
EXPECT_LONGS_EQUAL(1, actual2.size());
EXPECT(assert_equal(A1 * x1 + b, actual2[X(0)], 50 * sigma));
// Use a specific random generator
std::mt19937_64 rng(4242);
auto actual3 = conditional.sample(given, &rng);
EXPECT_LONGS_EQUAL(1, actual2.size());
// regression is not repeatable across platforms/versions :-(
// EXPECT(assert_equal(Vector2(31.0111856, 64.9850775), actual2[X(0)], 1e-5));
}
/* ************************************************************************* */
int main() {
TestResult tr;
return TestRegistry::runAllTests(tr);
}
/* ************************************************************************* */

View File

@ -17,10 +17,13 @@
**/
#include <gtsam/linear/GaussianDensity.h>
#include <gtsam/inference/Symbol.h>
#include <CppUnitLite/TestHarness.h>
using namespace gtsam;
using namespace std;
using symbol_shorthand::X;
/* ************************************************************************* */
TEST(GaussianDensity, constructor)
@ -37,6 +40,22 @@ TEST(GaussianDensity, constructor)
EXPECT(assert_equal(s, copied.get_model()->sigmas()));
}
/* ************************************************************************* */
// Test FromMeanAndStddev named constructor
TEST(GaussianDensity, FromMeanAndStddev) {
Matrix A1 = (Matrix(2, 2) << 1., 2., 3., 4.).finished();
const Vector2 b(20, 40), x0(1, 2);
const double sigma = 3;
VectorValues values;
values.insert(X(0), x0);
auto density = GaussianDensity::FromMeanAndStddev(X(0), b, sigma);
Vector2 e = (x0 - b) / sigma;
double expected = 0.5 * e.dot(e);
EXPECT_DOUBLES_EQUAL(expected, density.error(values), 1e-9);
}
/* ************************************************************************* */
int main() { TestResult tr; return TestRegistry::runAllTests(tr);}
/* ************************************************************************* */

View File

@ -112,54 +112,50 @@ TEST( GaussianBayesTree, linear_smoother_shortcuts )
C4 x7 : x6
************************************************************************* */
TEST( GaussianBayesTree, balanced_smoother_marginals )
{
TEST(GaussianBayesTree, balanced_smoother_marginals) {
// Create smoother with 7 nodes
GaussianFactorGraph smoother = createSmoother(7);
// Create the Bayes tree
Ordering ordering;
ordering += X(1),X(3),X(5),X(7),X(2),X(6),X(4);
ordering += X(1), X(3), X(5), X(7), X(2), X(6), X(4);
GaussianBayesTree bayesTree = *smoother.eliminateMultifrontal(ordering);
VectorValues actualSolution = bayesTree.optimize();
VectorValues expectedSolution = VectorValues::Zero(actualSolution);
EXPECT(assert_equal(expectedSolution,actualSolution,tol));
EXPECT(assert_equal(expectedSolution, actualSolution, tol));
LONGS_EQUAL(4, (long)bayesTree.size());
LONGS_EQUAL(4, bayesTree.size());
double tol=1e-5;
double tol = 1e-5;
// Check marginal on x1
JacobianFactor expected1 = GaussianDensity::FromMeanAndStddev(X(1), Z_2x1, sigmax1);
JacobianFactor actual1 = *bayesTree.marginalFactor(X(1));
Matrix expectedCovarianceX1 = I_2x2 * (sigmax1 * sigmax1);
Matrix actualCovarianceX1;
GaussianFactor::shared_ptr m = bayesTree.marginalFactor(X(1), EliminateCholesky);
actualCovarianceX1 = bayesTree.marginalFactor(X(1), EliminateCholesky)->information().inverse();
EXPECT(assert_equal(expectedCovarianceX1, actualCovarianceX1, tol));
EXPECT(assert_equal(expected1,actual1,tol));
Matrix expectedCovX1 = I_2x2 * (sigmax1 * sigmax1);
auto m = bayesTree.marginalFactor(X(1), EliminateCholesky);
Matrix actualCovarianceX1 = m->information().inverse();
EXPECT(assert_equal(expectedCovX1, actualCovarianceX1, tol));
// Check marginal on x2
double sigx2 = 0.68712938; // FIXME: this should be corrected analytically
JacobianFactor expected2 = GaussianDensity::FromMeanAndStddev(X(2), Z_2x1, sigx2);
double sigmax2 = 0.68712938; // FIXME: this should be corrected analytically
JacobianFactor actual2 = *bayesTree.marginalFactor(X(2));
EXPECT(assert_equal(expected2,actual2,tol));
Matrix expectedCovX2 = I_2x2 * (sigmax2 * sigmax2);
EXPECT(assert_equal(expectedCovX2, actual2.information().inverse(), tol));
// Check marginal on x3
JacobianFactor expected3 = GaussianDensity::FromMeanAndStddev(X(3), Z_2x1, sigmax3);
JacobianFactor actual3 = *bayesTree.marginalFactor(X(3));
EXPECT(assert_equal(expected3,actual3,tol));
Matrix expectedCovX3 = I_2x2 * (sigmax3 * sigmax3);
EXPECT(assert_equal(expectedCovX3, actual3.information().inverse(), tol));
// Check marginal on x4
JacobianFactor expected4 = GaussianDensity::FromMeanAndStddev(X(4), Z_2x1, sigmax4);
JacobianFactor actual4 = *bayesTree.marginalFactor(X(4));
EXPECT(assert_equal(expected4,actual4,tol));
Matrix expectedCovX4 = I_2x2 * (sigmax4 * sigmax4);
EXPECT(assert_equal(expectedCovX4, actual4.information().inverse(), tol));
// Check marginal on x7 (should be equal to x1)
JacobianFactor expected7 = GaussianDensity::FromMeanAndStddev(X(7), Z_2x1, sigmax7);
JacobianFactor actual7 = *bayesTree.marginalFactor(X(7));
EXPECT(assert_equal(expected7,actual7,tol));
Matrix expectedCovX7 = I_2x2 * (sigmax7 * sigmax7);
EXPECT(assert_equal(expectedCovX7, actual7.information().inverse(), tol));
}
/* ************************************************************************* */