gtsam/gtsam/linear/SubgraphPreconditioner.h

117 lines
3.8 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 SubgraphPreconditioner.h
// * @date Dec 31, 2009
// * @author Frank Dellaert
// */
//
//#pragma once
//
//#include <gtsam/linear/JacobianFactor.h>
//#include <gtsam/linear/GaussianBayesNet.h>
//#include <gtsam/nonlinear/Ordering.h> // FIXME shouldn't have nonlinear things in linear
//
//namespace gtsam {
//
// /**
// * Subgraph conditioner class, as explained in the RSS 2010 submission.
// * Starting with a graph A*x=b, we split it in two systems A1*x=b1 and A2*x=b2
// * We solve R1*x=c1, and make the substitution y=R1*x-c1.
// * To use the class, give the Bayes Net R1*x=c1 and Graph A2*x=b2.
// * Then solve for yhat using CG, and solve for xhat = system.x(yhat).
// */
// class SubgraphPreconditioner {
//
// public:
// typedef boost::shared_ptr<const GaussianBayesNet> sharedBayesNet;
// typedef boost::shared_ptr<const FactorGraph<JacobianFactor> > sharedFG;
// typedef boost::shared_ptr<const VectorValues> sharedValues;
// typedef boost::shared_ptr<const Errors> sharedErrors;
//
// private:
// sharedFG Ab1_, Ab2_;
// sharedBayesNet Rc1_;
// sharedValues xbar_;
// sharedErrors b2bar_; /** b2 - A2*xbar */
//
// public:
//
// SubgraphPreconditioner();
// /**
// * Constructor
// * @param Ab1: the Graph A1*x=b1
// * @param Ab2: the Graph A2*x=b2
// * @param Rc1: the Bayes Net R1*x=c1
// * @param xbar: the solution to R1*x=c1
// */
// SubgraphPreconditioner(const sharedFG& Ab1, const sharedFG& Ab2, const sharedBayesNet& Rc1, const sharedValues& xbar);
//
// /** Access Ab1 */
// const sharedFG& Ab1() const { return Ab1_; }
//
// /** Access Ab2 */
// const sharedFG& Ab2() const { return Ab2_; }
//
// /** Access Rc1 */
// const sharedBayesNet& Rc1() const { return Rc1_; }
//
// /**
// * Add zero-mean i.i.d. Gaussian prior terms to each variable
// * @param sigma Standard deviation of Gaussian
// */
//// SubgraphPreconditioner add_priors(double sigma) const;
//
// /* x = xbar + inv(R1)*y */
// VectorValues x(const VectorValues& y) const;
//
// /* A zero VectorValues with the structure of xbar */
// VectorValues zero() const {
// VectorValues V(VectorValues::Zero(*xbar_)) ;
// return V ;
// }
//
// /**
// * Add constraint part of the error only, used in both calls above
// * y += alpha*inv(R1')*A2'*e2
// * Takes a range indicating e2 !!!!
// */
// void transposeMultiplyAdd2(double alpha, Errors::const_iterator begin,
// Errors::const_iterator end, VectorValues& y) const;
//
// /** print the object */
// void print(const std::string& s = "SubgraphPreconditioner") const;
// };
//
// /* error, given y */
// double error(const SubgraphPreconditioner& sp, const VectorValues& y);
//
// /** gradient = y + inv(R1')*A2'*(A2*inv(R1)*y-b2bar) */
// VectorValues gradient(const SubgraphPreconditioner& sp, const VectorValues& y);
//
// /** Apply operator A */
// Errors operator*(const SubgraphPreconditioner& sp, const VectorValues& y);
//
// /** Apply operator A in place: needs e allocated already */
// void multiplyInPlace(const SubgraphPreconditioner& sp, const VectorValues& y, Errors& e);
//
// /** Apply operator A' */
// VectorValues operator^(const SubgraphPreconditioner& sp, const Errors& e);
//
// /**
// * Add A'*e to y
// * y += alpha*A'*[e1;e2] = [alpha*e1; alpha*inv(R1')*A2'*e2]
// */
// void transposeMultiplyAdd(const SubgraphPreconditioner& sp, double alpha, const Errors& e, VectorValues& y);
//
//} // namespace gtsam