gtsam/tests/smallExample.cpp

500 lines
14 KiB
C++

/* ----------------------------------------------------------------------------
* GTSAM Copyright 2010, Georgia Tech Research Corporation,
* Atlanta, Georgia 30332-0415
* All Rights Reserved
* Authors: Frank Dellaert, et al. (see THANKS for the full author list)
* See LICENSE for the license information
* -------------------------------------------------------------------------- */
/**
* @file smallExample.cpp
* @brief Create small example with two poses and one landmark
* @brief smallExample
* @author Carlos Nieto
* @author Frank dellaert
*/
#include <gtsam/nonlinear/Symbol.h>
#include <gtsam/nonlinear/Ordering.h>
#include <gtsam/nonlinear/NonlinearFactorGraph.h>
#include <gtsam/nonlinear/NonlinearFactor.h>
#include <gtsam/inference/FactorGraph.h>
#include <gtsam/base/Matrix.h>
#include <tests/smallExample.h>
#include <boost/optional.hpp>
#include <boost/shared_ptr.hpp>
#include <iostream>
#include <string>
using namespace std;
namespace gtsam {
namespace example {
typedef boost::shared_ptr<NonlinearFactor> shared;
static SharedDiagonal sigma1_0 = noiseModel::Isotropic::Sigma(2,1.0);
static SharedDiagonal sigma0_1 = noiseModel::Isotropic::Sigma(2,0.1);
static SharedDiagonal sigma0_2 = noiseModel::Isotropic::Sigma(2,0.2);
static SharedDiagonal constraintModel = noiseModel::Constrained::All(2);
static const Index _l1_=0, _x1_=1, _x2_=2;
static const Index _x_=0, _y_=1, _z_=2;
// Convenience for named keys
using symbol_shorthand::X;
using symbol_shorthand::L;
/* ************************************************************************* */
boost::shared_ptr<const Graph> sharedNonlinearFactorGraph() {
// Create
boost::shared_ptr<Graph> nlfg(
new Graph);
// prior on x1
Point2 mu;
shared f1(new simulated2D::Prior(mu, sigma0_1, X(1)));
nlfg->push_back(f1);
// odometry between x1 and x2
Point2 z2(1.5, 0);
shared f2(new simulated2D::Odometry(z2, sigma0_1, X(1), X(2)));
nlfg->push_back(f2);
// measurement between x1 and l1
Point2 z3(0, -1);
shared f3(new simulated2D::Measurement(z3, sigma0_2, X(1), L(1)));
nlfg->push_back(f3);
// measurement between x2 and l1
Point2 z4(-1.5, -1.);
shared f4(new simulated2D::Measurement(z4, sigma0_2, X(2), L(1)));
nlfg->push_back(f4);
return nlfg;
}
/* ************************************************************************* */
Graph createNonlinearFactorGraph() {
return *sharedNonlinearFactorGraph();
}
/* ************************************************************************* */
Values createValues() {
Values c;
c.insert(X(1), Point2(0.0, 0.0));
c.insert(X(2), Point2(1.5, 0.0));
c.insert(L(1), Point2(0.0, -1.0));
return c;
}
/* ************************************************************************* */
VectorValues createVectorValues() {
VectorValues c(vector<size_t>(3, 2));
c[_l1_] = Vector_(2, 0.0, -1.0);
c[_x1_] = Vector_(2, 0.0, 0.0);
c[_x2_] = Vector_(2, 1.5, 0.0);
return c;
}
/* ************************************************************************* */
boost::shared_ptr<const Values> sharedNoisyValues() {
boost::shared_ptr<Values> c(new Values);
c->insert(X(1), Point2(0.1, 0.1));
c->insert(X(2), Point2(1.4, 0.2));
c->insert(L(1), Point2(0.1, -1.1));
return c;
}
/* ************************************************************************* */
Values createNoisyValues() {
return *sharedNoisyValues();
}
/* ************************************************************************* */
VectorValues createCorrectDelta(const Ordering& ordering) {
VectorValues c(vector<size_t>(3,2));
c[ordering[L(1)]] = Vector_(2, -0.1, 0.1);
c[ordering[X(1)]] = Vector_(2, -0.1, -0.1);
c[ordering[X(2)]] = Vector_(2, 0.1, -0.2);
return c;
}
/* ************************************************************************* */
VectorValues createZeroDelta(const Ordering& ordering) {
VectorValues c(vector<size_t>(3,2));
c[ordering[L(1)]] = zero(2);
c[ordering[X(1)]] = zero(2);
c[ordering[X(2)]] = zero(2);
return c;
}
/* ************************************************************************* */
JacobianFactorGraph createGaussianFactorGraph(const Ordering& ordering) {
// Create empty graph
JacobianFactorGraph fg;
SharedDiagonal unit2 = noiseModel::Unit::Create(2);
// linearized prior on x1: c[_x1_]+x1=0 i.e. x1=-c[_x1_]
fg.push_back(boost::make_shared<JacobianFactor>(ordering[X(1)], 10*eye(2), -1.0*ones(2), unit2));
// odometry between x1 and x2: x2-x1=[0.2;-0.1]
fg.push_back(boost::make_shared<JacobianFactor>(ordering[X(1)], -10*eye(2),ordering[X(2)], 10*eye(2), Vector_(2, 2.0, -1.0), unit2));
// measurement between x1 and l1: l1-x1=[0.0;0.2]
fg.push_back(boost::make_shared<JacobianFactor>(ordering[X(1)], -5*eye(2), ordering[L(1)], 5*eye(2), Vector_(2, 0.0, 1.0), unit2));
// measurement between x2 and l1: l1-x2=[-0.2;0.3]
fg.push_back(boost::make_shared<JacobianFactor>(ordering[X(2)], -5*eye(2), ordering[L(1)], 5*eye(2), Vector_(2, -1.0, 1.5), unit2));
return fg;
}
/* ************************************************************************* */
/** create small Chordal Bayes Net x <- y
* x y d
* 1 1 9
* 1 5
*/
GaussianBayesNet createSmallGaussianBayesNet() {
Matrix R11 = Matrix_(1, 1, 1.0), S12 = Matrix_(1, 1, 1.0);
Matrix R22 = Matrix_(1, 1, 1.0);
Vector d1(1), d2(1);
d1(0) = 9;
d2(0) = 5;
Vector tau(1);
tau(0) = 1.0;
// define nodes and specify in reverse topological sort (i.e. parents last)
GaussianConditional::shared_ptr Px_y(new GaussianConditional(_x_, d1, R11, _y_, S12, tau));
GaussianConditional::shared_ptr Py(new GaussianConditional(_y_, d2, R22, tau));
GaussianBayesNet cbn;
cbn.push_back(Px_y);
cbn.push_back(Py);
return cbn;
}
/* ************************************************************************* */
// Some nonlinear functions to optimize
/* ************************************************************************* */
namespace smallOptimize {
Point2 h(const Point2& v) {
return Point2(cos(v.x()), sin(v.y()));
}
Matrix H(const Point2& v) {
return Matrix_(2, 2,
-sin(v.x()), 0.0,
0.0, cos(v.y()));
}
struct UnaryFactor: public gtsam::NoiseModelFactor1<Point2> {
Point2 z_;
UnaryFactor(const Point2& z, const SharedNoiseModel& model, Key key) :
gtsam::NoiseModelFactor1<Point2>(model, key), z_(z) {
}
Vector evaluateError(const Point2& x, boost::optional<Matrix&> A = boost::none) const {
if (A) *A = H(x);
return (h(x) - z_).vector();
}
};
}
/* ************************************************************************* */
boost::shared_ptr<const Graph> sharedReallyNonlinearFactorGraph() {
boost::shared_ptr<Graph> fg(new Graph);
Vector z = Vector_(2, 1.0, 0.0);
double sigma = 0.1;
boost::shared_ptr<smallOptimize::UnaryFactor> factor(
new smallOptimize::UnaryFactor(z, noiseModel::Isotropic::Sigma(2,sigma), X(1)));
fg->push_back(factor);
return fg;
}
Graph createReallyNonlinearFactorGraph() {
return *sharedReallyNonlinearFactorGraph();
}
/* ************************************************************************* */
pair<Graph, Values> createNonlinearSmoother(int T) {
// Create
Graph nlfg;
Values poses;
// prior on x1
Point2 x1(1.0, 0.0);
shared prior(new simulated2D::Prior(x1, sigma1_0, X(1)));
nlfg.push_back(prior);
poses.insert(X(1), x1);
for (int t = 2; t <= T; t++) {
// odometry between x_t and x_{t-1}
Point2 odo(1.0, 0.0);
shared odometry(new simulated2D::Odometry(odo, sigma1_0, X(t - 1), X(t)));
nlfg.push_back(odometry);
// measurement on x_t is like perfect GPS
Point2 xt(t, 0);
shared measurement(new simulated2D::Prior(xt, sigma1_0, X(t)));
nlfg.push_back(measurement);
// initial estimate
poses.insert(X(t), xt);
}
return make_pair(nlfg, poses);
}
/* ************************************************************************* */
pair<FactorGraph<GaussianFactor>, Ordering> createSmoother(int T, boost::optional<Ordering> ordering) {
Graph nlfg;
Values poses;
boost::tie(nlfg, poses) = createNonlinearSmoother(T);
if(!ordering) ordering = *poses.orderingArbitrary();
return make_pair(*nlfg.linearize(poses, *ordering), *ordering);
}
/* ************************************************************************* */
JacobianFactorGraph createSimpleConstraintGraph() {
// create unary factor
// prior on _x_, mean = [1,-1], sigma=0.1
Matrix Ax = eye(2);
Vector b1(2);
b1(0) = 1.0;
b1(1) = -1.0;
JacobianFactor::shared_ptr f1(new JacobianFactor(_x_, Ax, b1, sigma0_1));
// create binary constraint factor
// between _x_ and _y_, that is going to be the only factor on _y_
// |1 0||x_1| + |-1 0||y_1| = |0|
// |0 1||x_2| | 0 -1||y_2| |0|
Matrix Ax1 = eye(2);
Matrix Ay1 = eye(2) * -1;
Vector b2 = Vector_(2, 0.0, 0.0);
JacobianFactor::shared_ptr f2(new JacobianFactor(_x_, Ax1, _y_, Ay1, b2,
constraintModel));
// construct the graph
JacobianFactorGraph fg;
fg.push_back(f1);
fg.push_back(f2);
return fg;
}
/* ************************************************************************* */
VectorValues createSimpleConstraintValues() {
VectorValues config(vector<size_t>(2,2));
Vector v = Vector_(2, 1.0, -1.0);
config[_x_] = v;
config[_y_] = v;
return config;
}
/* ************************************************************************* */
JacobianFactorGraph createSingleConstraintGraph() {
// create unary factor
// prior on _x_, mean = [1,-1], sigma=0.1
Matrix Ax = eye(2);
Vector b1(2);
b1(0) = 1.0;
b1(1) = -1.0;
//GaussianFactor::shared_ptr f1(new JacobianFactor(_x_, sigma0_1->Whiten(Ax), sigma0_1->whiten(b1), sigma0_1));
JacobianFactor::shared_ptr f1(new JacobianFactor(_x_, Ax, b1, sigma0_1));
// create binary constraint factor
// between _x_ and _y_, that is going to be the only factor on _y_
// |1 2||x_1| + |10 0||y_1| = |1|
// |2 1||x_2| |0 10||y_2| |2|
Matrix Ax1(2, 2);
Ax1(0, 0) = 1.0;
Ax1(0, 1) = 2.0;
Ax1(1, 0) = 2.0;
Ax1(1, 1) = 1.0;
Matrix Ay1 = eye(2) * 10;
Vector b2 = Vector_(2, 1.0, 2.0);
JacobianFactor::shared_ptr f2(new JacobianFactor(_x_, Ax1, _y_, Ay1, b2,
constraintModel));
// construct the graph
JacobianFactorGraph fg;
fg.push_back(f1);
fg.push_back(f2);
return fg;
}
/* ************************************************************************* */
VectorValues createSingleConstraintValues() {
VectorValues config(vector<size_t>(2,2));
config[_x_] = Vector_(2, 1.0, -1.0);
config[_y_] = Vector_(2, 0.2, 0.1);
return config;
}
/* ************************************************************************* */
JacobianFactorGraph createMultiConstraintGraph() {
// unary factor 1
Matrix A = eye(2);
Vector b = Vector_(2, -2.0, 2.0);
JacobianFactor::shared_ptr lf1(new JacobianFactor(_x_, A, b, sigma0_1));
// constraint 1
Matrix A11(2, 2);
A11(0, 0) = 1.0;
A11(0, 1) = 2.0;
A11(1, 0) = 2.0;
A11(1, 1) = 1.0;
Matrix A12(2, 2);
A12(0, 0) = 10.0;
A12(0, 1) = 0.0;
A12(1, 0) = 0.0;
A12(1, 1) = 10.0;
Vector b1(2);
b1(0) = 1.0;
b1(1) = 2.0;
JacobianFactor::shared_ptr lc1(new JacobianFactor(_x_, A11, _y_, A12, b1,
constraintModel));
// constraint 2
Matrix A21(2, 2);
A21(0, 0) = 3.0;
A21(0, 1) = 4.0;
A21(1, 0) = -1.0;
A21(1, 1) = -2.0;
Matrix A22(2, 2);
A22(0, 0) = 1.0;
A22(0, 1) = 1.0;
A22(1, 0) = 1.0;
A22(1, 1) = 2.0;
Vector b2(2);
b2(0) = 3.0;
b2(1) = 4.0;
JacobianFactor::shared_ptr lc2(new JacobianFactor(_x_, A21, _z_, A22, b2,
constraintModel));
// construct the graph
JacobianFactorGraph fg;
fg.push_back(lf1);
fg.push_back(lc1);
fg.push_back(lc2);
return fg;
}
/* ************************************************************************* */
VectorValues createMultiConstraintValues() {
VectorValues config(vector<size_t>(3,2));
config[_x_] = Vector_(2, -2.0, 2.0);
config[_y_] = Vector_(2, -0.1, 0.4);
config[_z_] = Vector_(2, -4.0, 5.0);
return config;
}
/* ************************************************************************* */
// Create key for simulated planar graph
Symbol key(int x, int y) {
return X(1000*x+y);
}
/* ************************************************************************* */
boost::tuple<GaussianFactorGraph, VectorValues> planarGraph(size_t N) {
// create empty graph
NonlinearFactorGraph nlfg;
// Create almost hard constraint on x11, sigma=0 will work for PCG not for normal
shared constraint(new simulated2D::Prior(Point2(1.0, 1.0), sharedSigma(2,1e-3), key(1,1)));
nlfg.push_back(constraint);
// Create horizontal constraints, 1...N*(N-1)
Point2 z1(1.0, 0.0); // move right
for (size_t x = 1; x < N; x++)
for (size_t y = 1; y <= N; y++) {
shared f(new simulated2D::Odometry(z1, sharedSigma(2,0.01), key(x, y), key(x + 1, y)));
nlfg.push_back(f);
}
// Create vertical constraints, N*(N-1)+1..2*N*(N-1)
Point2 z2(0.0, 1.0); // move up
for (size_t x = 1; x <= N; x++)
for (size_t y = 1; y < N; y++) {
shared f(new simulated2D::Odometry(z2, sharedSigma(2,0.01), key(x, y), key(x, y + 1)));
nlfg.push_back(f);
}
// Create linearization and ground xtrue config
Values zeros;
for (size_t x = 1; x <= N; x++)
for (size_t y = 1; y <= N; y++)
zeros.insert(key(x, y), Point2());
Ordering ordering(planarOrdering(N));
VectorValues xtrue(zeros.dims(ordering));
for (size_t x = 1; x <= N; x++)
for (size_t y = 1; y <= N; y++)
xtrue[ordering[key(x, y)]] = Point2(x,y).vector();
// linearize around zero
return boost::make_tuple(*nlfg.linearize(zeros, ordering), xtrue);
}
/* ************************************************************************* */
Ordering planarOrdering(size_t N) {
Ordering ordering;
for (size_t y = N; y >= 1; y--)
for (size_t x = N; x >= 1; x--)
ordering.push_back(key(x, y));
return ordering;
}
/* ************************************************************************* */
pair<JacobianFactorGraph, JacobianFactorGraph > splitOffPlanarTree(size_t N,
const JacobianFactorGraph& original) {
JacobianFactorGraph T, C;
// Add the x11 constraint to the tree
T.push_back(original[0]);
// Add all horizontal constraints to the tree
size_t i = 1;
for (size_t x = 1; x < N; x++)
for (size_t y = 1; y <= N; y++, i++)
T.push_back(original[i]);
// Add first vertical column of constraints to T, others to C
for (size_t x = 1; x <= N; x++)
for (size_t y = 1; y < N; y++, i++)
if (x == 1)
T.push_back(original[i]);
else
C.push_back(original[i]);
return make_pair(T, C);
}
/* ************************************************************************* */
} // example
} // namespace gtsam