gtsam/gtsam/base/SymmetricBlockMatrix.h

230 lines
8.9 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/Matrix.h>
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()).
*
* @addtogroup base */
class SymmetricBlockMatrix
{
public:
typedef SymmetricBlockMatrix This;
typedef Eigen::Block<Matrix> Block;
typedef Eigen::Block<const Matrix> constBlock;
protected:
Matrix matrix_; ///< The full matrix
std::vector<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() :
blockStart_(0)
{
variableColOffsets_.push_back(0);
assertInvariants();
}
/** Construct from a container of the sizes of each block. */
template<typename CONTAINER>
SymmetricBlockMatrix(const CONTAINER& dimensions) :
blockStart_(0)
{
fillOffsets(dimensions.begin(), dimensions.end());
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) :
blockStart_(0)
{
fillOffsets(firstBlockDim, lastBlockDim);
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) :
matrix_(matrix), blockStart_(0)
{
fillOffsets(dimensions.begin(), dimensions.end());
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 { assertInvariants(); return variableColOffsets_.size() - 1 - blockStart_; }
Block operator()(DenseIndex i_block, DenseIndex j_block) {
return range(i_block, i_block+1, j_block, j_block+1);
}
constBlock operator()(DenseIndex i_block, DenseIndex j_block) const {
return range(i_block, i_block+1, j_block, j_block+1);
}
Block range(DenseIndex i_startBlock, DenseIndex i_endBlock, DenseIndex j_startBlock, DenseIndex j_endBlock) {
assertInvariants();
DenseIndex i_actualStartBlock = i_startBlock + blockStart_;
DenseIndex i_actualEndBlock = i_endBlock + blockStart_;
DenseIndex j_actualStartBlock = j_startBlock + blockStart_;
DenseIndex j_actualEndBlock = j_endBlock + blockStart_;
checkBlock(i_actualStartBlock);
checkBlock(j_actualStartBlock);
if(i_startBlock != 0 || i_endBlock != 0) {
checkBlock(i_actualStartBlock);
assert(i_actualEndBlock < (DenseIndex)variableColOffsets_.size());
}
if(j_startBlock != 0 || j_endBlock != 0) {
checkBlock(j_actualStartBlock);
assert(j_actualEndBlock < (DenseIndex)variableColOffsets_.size());
}
return matrix_.block(
variableColOffsets_[i_actualStartBlock], variableColOffsets_[j_actualStartBlock],
variableColOffsets_[i_actualEndBlock] - variableColOffsets_[i_actualStartBlock],
variableColOffsets_[j_actualEndBlock] - variableColOffsets_[j_actualStartBlock]);
}
constBlock range(DenseIndex i_startBlock, DenseIndex i_endBlock, DenseIndex j_startBlock, DenseIndex j_endBlock) const {
assertInvariants();
DenseIndex i_actualStartBlock = i_startBlock + blockStart_;
DenseIndex i_actualEndBlock = i_endBlock + blockStart_;
DenseIndex j_actualStartBlock = j_startBlock + blockStart_;
DenseIndex j_actualEndBlock = j_endBlock + blockStart_;
if(i_startBlock != 0 || i_endBlock != 0) {
checkBlock(i_actualStartBlock);
assert(i_actualEndBlock < (DenseIndex)variableColOffsets_.size());
}
if(j_startBlock != 0 || j_endBlock != 0) {
checkBlock(j_actualStartBlock);
assert(j_actualEndBlock < (DenseIndex)variableColOffsets_.size());
}
return matrix_.block(
variableColOffsets_[i_actualStartBlock], variableColOffsets_[j_actualStartBlock],
variableColOffsets_[i_actualEndBlock] - variableColOffsets_[i_actualStartBlock],
variableColOffsets_[j_actualEndBlock] - variableColOffsets_[j_actualStartBlock]);
}
/** Return the full matrix, *not* including any portions excluded by firstBlock(). */
Block full() {
return range(0,nBlocks(), 0,nBlocks());
}
/** Return the full matrix, *not* including any portions excluded by firstBlock(). */
constBlock full() const {
return range(0,nBlocks(), 0,nBlocks());
}
/** Access to full matrix, including any portions excluded by firstBlock() to other operations. */
const Matrix& matrix() const { return matrix_; }
/** Access to full matrix, including any portions excluded by firstBlock() to other operations. */
Matrix& matrix() { return matrix_; }
DenseIndex offset(DenseIndex block) const {
assertInvariants();
DenseIndex actualBlock = block + blockStart_;
checkBlock(actualBlock);
return variableColOffsets_[actualBlock];
}
DenseIndex& blockStart() { return blockStart_; }
DenseIndex blockStart() const { return blockStart_; }
protected:
void assertInvariants() const {
assert(matrix_.rows() == matrix_.cols());
assert(matrix_.cols() == variableColOffsets_.back());
assert(blockStart_ < (DenseIndex)variableColOffsets_.size());
}
void checkBlock(DenseIndex block) const {
assert(matrix_.rows() == matrix_.cols());
assert(matrix_.cols() == variableColOffsets_.back());
assert(block < (DenseIndex)variableColOffsets_.size()-1);
assert(variableColOffsets_[block] < matrix_.cols() && variableColOffsets_[block+1] <= matrix_.cols());
}
template<typename ITERATOR>
void fillOffsets(ITERATOR firstBlockDim, ITERATOR lastBlockDim) {
variableColOffsets_.resize((lastBlockDim-firstBlockDim)+1);
variableColOffsets_[0] = 0;
DenseIndex j=0;
for(ITERATOR dim=firstBlockDim; dim!=lastBlockDim; ++dim) {
variableColOffsets_[j+1] = variableColOffsets_[j] + *dim;
++ j;
}
}
friend class VerticalBlockMatrix;
private:
/** Serialization function */
friend class boost::serialization::access;
template<class ARCHIVE>
void serialize(ARCHIVE & ar, const unsigned int version) {
ar & BOOST_SERIALIZATION_NVP(matrix_);
ar & BOOST_SERIALIZATION_NVP(variableColOffsets_);
ar & BOOST_SERIALIZATION_NVP(blockStart_);
}
};
}