gtsam/gtsam/base/SymmetricBlockMatrix.h

405 lines
15 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 SymmetricBlockMatrix.h
* @brief Access to matrices via blocks of pre-defined sizes. Used in GaussianFactor and GaussianConditional.
* @author Richard Roberts
* @date Sep 18, 2010
*/
#pragma once
#include <gtsam/base/FastVector.h>
#include <gtsam/base/Matrix.h>
#include <gtsam/base/types.h>
#include <gtsam/dllexport.h>
#include <boost/serialization/nvp.hpp>
#include <cassert>
#include <stdexcept>
#include <array>
namespace boost {
namespace serialization {
class access;
} /* namespace serialization */
} /* namespace boost */
namespace gtsam {
// Forward declarations
class VerticalBlockMatrix;
/**
* This class stores a dense matrix and allows it to be accessed as a collection of blocks. When
* constructed, the caller must provide the dimensions of the blocks.
*
* The block structure is symmetric, but the underlying matrix does not necessarily need to be.
*
* This class also has a parameter that can be changed after construction to change the apparent
* matrix view. firstBlock() determines the block that appears to have index 0 for all operations
* (except re-setting firstBlock()).
*
* @ingroup base */
class GTSAM_EXPORT SymmetricBlockMatrix
{
public:
typedef SymmetricBlockMatrix This;
typedef Eigen::Block<Matrix> Block;
typedef Eigen::Block<const Matrix> constBlock;
protected:
Matrix matrix_; ///< The full matrix
FastVector<DenseIndex> variableColOffsets_; ///< the starting columns of each block (0-based)
DenseIndex blockStart_; ///< Changes apparent matrix view, see main class comment.
public:
/// Construct from an empty matrix (asserts that the matrix is empty)
SymmetricBlockMatrix();
/// Construct from a container of the sizes of each block.
template<typename CONTAINER>
SymmetricBlockMatrix(const CONTAINER& dimensions, bool appendOneDimension = false) :
blockStart_(0)
{
fillOffsets(dimensions.begin(), dimensions.end(), appendOneDimension);
matrix_.resize(variableColOffsets_.back(), variableColOffsets_.back());
assertInvariants();
}
/// Construct from iterator over the sizes of each vertical block.
template<typename ITERATOR>
SymmetricBlockMatrix(ITERATOR firstBlockDim, ITERATOR lastBlockDim, bool appendOneDimension = false) :
blockStart_(0)
{
fillOffsets(firstBlockDim, lastBlockDim, appendOneDimension);
matrix_.resize(variableColOffsets_.back(), variableColOffsets_.back());
assertInvariants();
}
/// Construct from a container of the sizes of each vertical block and a pre-prepared matrix.
template<typename CONTAINER>
SymmetricBlockMatrix(const CONTAINER& dimensions, const Matrix& matrix, bool appendOneDimension = false) :
blockStart_(0)
{
matrix_.resize(matrix.rows(), matrix.cols());
matrix_.triangularView<Eigen::Upper>() = matrix.triangularView<Eigen::Upper>();
fillOffsets(dimensions.begin(), dimensions.end(), appendOneDimension);
if(matrix_.rows() != matrix_.cols())
throw std::invalid_argument("Requested to create a SymmetricBlockMatrix from a non-square matrix.");
if(variableColOffsets_.back() != matrix_.cols())
throw std::invalid_argument("Requested to create a SymmetricBlockMatrix with dimensions that do not sum to the total size of the provided matrix.");
assertInvariants();
}
/// Copy the block structure, but do not copy the matrix data. If blockStart() has been
/// modified, this copies the structure of the corresponding matrix view. In the destination
/// SymmetricBlockMatrix, blockStart() will be 0.
static SymmetricBlockMatrix LikeActiveViewOf(const SymmetricBlockMatrix& other);
/// Copy the block structure, but do not copy the matrix data. If blockStart() has been
/// modified, this copies the structure of the corresponding matrix view. In the destination
/// SymmetricBlockMatrix, blockStart() will be 0.
static SymmetricBlockMatrix LikeActiveViewOf(const VerticalBlockMatrix& other);
/// Row size
DenseIndex rows() const { assertInvariants(); return variableColOffsets_.back() - variableColOffsets_[blockStart_]; }
/// Column size
DenseIndex cols() const { return rows(); }
/// Block count
DenseIndex nBlocks() const { return nActualBlocks() - blockStart_; }
/// Number of dimensions for variable on this diagonal block.
DenseIndex getDim(DenseIndex block) const {
return calcIndices(block, block, 1, 1)[2];
}
/// @name Block getter methods.
/// @{
/// Get a copy of a block (anywhere in the matrix).
/// This method makes a copy - use the methods below if performance is critical.
Matrix block(DenseIndex I, DenseIndex J) const;
/// Return the J'th diagonal block as a self adjoint view.
Eigen::SelfAdjointView<Block, Eigen::Upper> diagonalBlock(DenseIndex J) {
return block_(J, J).selfadjointView<Eigen::Upper>();
}
/// Return the J'th diagonal block as a self adjoint view.
Eigen::SelfAdjointView<constBlock, Eigen::Upper> diagonalBlock(DenseIndex J) const {
return block_(J, J).selfadjointView<Eigen::Upper>();
}
/// Get the diagonal of the J'th diagonal block.
Vector diagonal(DenseIndex J) const {
return block_(J, J).diagonal();
}
/// Get block above the diagonal (I, J).
constBlock aboveDiagonalBlock(DenseIndex I, DenseIndex J) const {
assert(I < J);
return block_(I, J);
}
/// Return the square sub-matrix that contains blocks(i:j, i:j).
Eigen::SelfAdjointView<constBlock, Eigen::Upper> selfadjointView(
DenseIndex I, DenseIndex J) const {
assert(J > I);
return block_(I, I, J - I, J - I).selfadjointView<Eigen::Upper>();
}
/// Return the square sub-matrix that contains blocks(i:j, i:j) as a triangular view.
Eigen::TriangularView<constBlock, Eigen::Upper> triangularView(DenseIndex I,
DenseIndex J) const {
assert(J > I);
return block_(I, I, J - I, J - I).triangularView<Eigen::Upper>();
}
/// Get a range [i,j) from the matrix. Indices are in block units.
constBlock aboveDiagonalRange(DenseIndex i_startBlock,
DenseIndex i_endBlock,
DenseIndex j_startBlock,
DenseIndex j_endBlock) const {
assert(i_startBlock < j_startBlock);
assert(i_endBlock <= j_startBlock);
return block_(i_startBlock, j_startBlock, i_endBlock - i_startBlock,
j_endBlock - j_startBlock);
}
/// Get a range [i,j) from the matrix. Indices are in block units.
Block aboveDiagonalRange(DenseIndex i_startBlock, DenseIndex i_endBlock,
DenseIndex j_startBlock, DenseIndex j_endBlock) {
assert(i_startBlock < j_startBlock);
assert(i_endBlock <= j_startBlock);
return block_(i_startBlock, j_startBlock, i_endBlock - i_startBlock,
j_endBlock - j_startBlock);
}
/// @}
/// @name Block setter methods.
/// @{
/// Set a diagonal block. Only the upper triangular portion of `xpr` is evaluated.
template <typename XprType>
void setDiagonalBlock(DenseIndex I, const XprType& xpr) {
block_(I, I).triangularView<Eigen::Upper>() = xpr.template triangularView<Eigen::Upper>();
}
/// Set an off-diagonal block. Only the upper triangular portion of `xpr` is evaluated.
template <typename XprType>
void setOffDiagonalBlock(DenseIndex I, DenseIndex J, const XprType& xpr) {
assert(I != J);
if (I < J) {
block_(I, J) = xpr;
} else {
block_(J, I) = xpr.transpose();
}
}
/// Increment the diagonal block by the values in `xpr`. Only reads the upper triangular part of `xpr`.
template <typename XprType>
void updateDiagonalBlock(DenseIndex I, const XprType& xpr) {
// TODO(gareth): Eigen won't let us add triangular or self-adjoint views
// here, so we do it manually.
auto dest = block_(I, I);
assert(dest.rows() == xpr.rows());
assert(dest.cols() == xpr.cols());
for (DenseIndex col = 0; col < dest.cols(); ++col) {
for (DenseIndex row = 0; row <= col; ++row) {
dest(row, col) += xpr(row, col);
}
}
}
/// Update an off diagonal block.
/// NOTE(emmett): This assumes noalias().
template <typename XprType>
void updateOffDiagonalBlock(DenseIndex I, DenseIndex J, const XprType& xpr) {
assert(I != J);
if (I < J) {
block_(I, J).noalias() += xpr;
} else {
block_(J, I).noalias() += xpr.transpose();
}
}
/// @}
/// @name Accessing the full matrix.
/// @{
/// Get self adjoint view.
Eigen::SelfAdjointView<Block, Eigen::Upper> selfadjointView() {
return full().selfadjointView<Eigen::Upper>();
}
/// Get self adjoint view.
Eigen::SelfAdjointView<constBlock, Eigen::Upper> selfadjointView() const {
return full().selfadjointView<Eigen::Upper>();
}
/// Set the entire active matrix. Only reads the upper triangular part of `xpr`.
template <typename XprType>
void setFullMatrix(const XprType& xpr) {
full().triangularView<Eigen::Upper>() = xpr.template triangularView<Eigen::Upper>();
}
/// Set the entire active matrix zero.
void setZero() {
full().triangularView<Eigen::Upper>().setZero();
}
/// Negate the entire active matrix.
void negate();
/// Invert the entire active matrix in place.
void invertInPlace();
/// @}
/// Retrieve or modify the first logical block, i.e. the block referenced by block index 0.
/// Blocks before it will be inaccessible, except by accessing the underlying matrix using
/// matrix().
DenseIndex& blockStart() { return blockStart_; }
/// Retrieve the first logical block, i.e. the block referenced by block index 0. Blocks before
/// it will be inaccessible, except by accessing the underlying matrix using matrix().
DenseIndex blockStart() const { return blockStart_; }
/**
* Given the augmented Hessian [A1'A1 A1'A2 A1'b
* A2'A1 A2'A2 A2'b
* b'A1 b'A2 b'b]
* on x1 and x2, does partial Cholesky in-place to obtain [R Sd;0 L] such that
* R'R = A1'A1
* R'Sd = [A1'A2 A1'b]
* L'L is the augmented Hessian on the the separator x2
* R and Sd can be interpreted as a GaussianConditional |R*x1 + S*x2 - d]^2
*/
void choleskyPartial(DenseIndex nFrontals);
/**
* After partial Cholesky, we can optionally split off R and Sd, to be interpreted as
* a GaussianConditional |R*x1 + S*x2 - d]^2. We leave the symmetric lower block L in place,
* and adjust block_start so now *this refers to it.
*/
VerticalBlockMatrix split(DenseIndex nFrontals);
protected:
/// Number of offsets in the full matrix.
DenseIndex nOffsets() const {
return variableColOffsets_.size();
}
/// Number of actual blocks in the full matrix.
DenseIndex nActualBlocks() const {
return nOffsets() - 1;
}
/// Get an offset for a block index (in the active view).
DenseIndex offset(DenseIndex block) const {
assert(block >= 0);
const DenseIndex actual_index = block + blockStart();
assert(actual_index < nOffsets());
return variableColOffsets_[actual_index];
}
/// Get an arbitrary block from the matrix. Indices are in block units.
constBlock block_(DenseIndex iBlock, DenseIndex jBlock,
DenseIndex blockRows = 1, DenseIndex blockCols = 1) const {
const std::array<DenseIndex, 4> indices =
calcIndices(iBlock, jBlock, blockRows, blockCols);
return matrix_.block(indices[0], indices[1], indices[2], indices[3]);
}
/// Get an arbitrary block from the matrix. Indices are in block units.
Block block_(DenseIndex iBlock, DenseIndex jBlock, DenseIndex blockRows = 1,
DenseIndex blockCols = 1) {
const std::array<DenseIndex, 4> indices =
calcIndices(iBlock, jBlock, blockRows, blockCols);
return matrix_.block(indices[0], indices[1], indices[2], indices[3]);
}
/// Get the full matrix as a block.
constBlock full() const {
return block_(0, 0, nBlocks(), nBlocks());
}
/// Get the full matrix as a block.
Block full() {
return block_(0, 0, nBlocks(), nBlocks());
}
/// Compute the indices into the underlying matrix for a given block.
std::array<DenseIndex, 4> calcIndices(DenseIndex iBlock, DenseIndex jBlock,
DenseIndex blockRows,
DenseIndex blockCols) const {
assert(blockRows >= 0);
assert(blockCols >= 0);
// adjust indices to account for start and size of blocks
const DenseIndex denseI = offset(iBlock);
const DenseIndex denseJ = offset(jBlock);
const DenseIndex denseRows = offset(iBlock + blockRows) - denseI;
const DenseIndex denseCols = offset(jBlock + blockCols) - denseJ;
return {{denseI, denseJ, denseRows, denseCols}};
}
void assertInvariants() const
{
assert(matrix_.rows() == matrix_.cols());
assert(matrix_.cols() == variableColOffsets_.back());
assert(blockStart_ < (DenseIndex)variableColOffsets_.size());
}
template<typename ITERATOR>
void fillOffsets(ITERATOR firstBlockDim, ITERATOR lastBlockDim, bool appendOneDimension)
{
variableColOffsets_.resize((lastBlockDim-firstBlockDim) + 1 + (appendOneDimension ? 1 : 0));
variableColOffsets_[0] = 0;
DenseIndex j=0;
for(ITERATOR dim=firstBlockDim; dim!=lastBlockDim; ++dim) {
variableColOffsets_[j+1] = variableColOffsets_[j] + *dim;
++ j;
}
if(appendOneDimension)
{
variableColOffsets_[j+1] = variableColOffsets_[j] + 1;
++ j;
}
}
friend class VerticalBlockMatrix;
template<typename SymmetricBlockMatrixType> friend class SymmetricBlockMatrixBlockExpr;
private:
/** Serialization function */
friend class boost::serialization::access;
template<class ARCHIVE>
void serialize(ARCHIVE & ar, const unsigned int /*version*/) {
// Fill in the lower triangle part of the matrix, so boost::serialization won't
// complain about uninitialized data with an input_stream_error exception
// http://www.boost.org/doc/libs/1_37_0/libs/serialization/doc/exceptions.html#stream_error
matrix_.triangularView<Eigen::Lower>() = matrix_.triangularView<Eigen::Upper>().transpose();
ar & BOOST_SERIALIZATION_NVP(matrix_);
ar & BOOST_SERIALIZATION_NVP(variableColOffsets_);
ar & BOOST_SERIALIZATION_NVP(blockStart_);
}
};
/// Foward declare exception class
class CholeskyFailed;
}