gtsam/gtsam/nonlinear/Expression-inl.h

289 lines
9.0 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 Expression-inl.h
* @date September 18, 2014
* @author Frank Dellaert
* @author Paul Furgale
* @brief Internals for Expression.h, not for general consumption
*/
#pragma once
#include <gtsam/nonlinear/internal/ExpressionNode.h>
#include <boost/tuple/tuple.hpp>
#include <boost/range/adaptor/map.hpp>
#include <boost/range/algorithm.hpp>
namespace gtsam {
template<typename T>
Expression<T>::Expression(const T& value) :
root_(new internal::ConstantExpression<T>(value)) {
}
template<typename T>
Expression<T>::Expression(const Key& key) :
root_(new internal::LeafExpression<T>(key)) {
}
template<typename T>
Expression<T>::Expression(const Symbol& symbol) :
root_(new internal::LeafExpression<T>(symbol)) {
}
template<typename T>
Expression<T>::Expression(unsigned char c, std::uint64_t j) :
root_(new internal::LeafExpression<T>(Symbol(c, j))) {
}
/// Construct a unary function expression
template<typename T>
template<typename A>
Expression<T>::Expression(typename UnaryFunction<A>::type function,
const Expression<A>& expression) :
root_(new internal::UnaryExpression<T, A>(function, expression)) {
}
/// Construct a binary function expression
template<typename T>
template<typename A1, typename A2>
Expression<T>::Expression(typename BinaryFunction<A1, A2>::type function,
const Expression<A1>& expression1, const Expression<A2>& expression2) :
root_(
new internal::BinaryExpression<T, A1, A2>(function, expression1,
expression2)) {
}
/// Construct a ternary function expression
template<typename T>
template<typename A1, typename A2, typename A3>
Expression<T>::Expression(typename TernaryFunction<A1, A2, A3>::type function,
const Expression<A1>& expression1, const Expression<A2>& expression2,
const Expression<A3>& expression3) :
root_(
new internal::TernaryExpression<T, A1, A2, A3>(function, expression1,
expression2, expression3)) {
}
/// Construct a nullary method expression
template<typename T>
template<typename A>
Expression<T>::Expression(const Expression<A>& expression,
T (A::*method)(typename MakeOptionalJacobian<T, A>::type) const) :
root_(
new internal::UnaryExpression<T, A>(boost::bind(method, _1, _2),
expression)) {
}
/// Construct a unary method expression
template<typename T>
template<typename A1, typename A2>
Expression<T>::Expression(const Expression<A1>& expression1,
T (A1::*method)(const A2&, typename MakeOptionalJacobian<T, A1>::type,
typename MakeOptionalJacobian<T, A2>::type) const,
const Expression<A2>& expression2) :
root_(
new internal::BinaryExpression<T, A1, A2>(
boost::bind(method, _1, _2, _3, _4), expression1, expression2)) {
}
/// Construct a binary method expression
template<typename T>
template<typename A1, typename A2, typename A3>
Expression<T>::Expression(const Expression<A1>& expression1,
T (A1::*method)(const A2&, const A3&,
typename MakeOptionalJacobian<T, A1>::type,
typename MakeOptionalJacobian<T, A2>::type,
typename MakeOptionalJacobian<T, A3>::type) const,
const Expression<A2>& expression2, const Expression<A3>& expression3) :
root_(
new internal::TernaryExpression<T, A1, A2, A3>(
boost::bind(method, _1, _2, _3, _4, _5, _6), expression1,
expression2, expression3)) {
}
template<typename T>
std::set<Key> Expression<T>::keys() const {
return root_->keys();
}
template<typename T>
void Expression<T>::dims(std::map<Key, int>& map) const {
root_->dims(map);
}
template<typename T>
void Expression<T>::print(const std::string& s) const {
root_->print(s);
}
template<typename T>
T Expression<T>::value(const Values& values,
boost::optional<std::vector<Matrix>&> H) const {
if (H) {
// Call private version that returns derivatives in H
KeysAndDims pair = keysAndDims();
return valueAndDerivatives(values, pair.first, pair.second, *H);
} else
// no derivatives needed, just return value
return root_->value(values);
}
template<typename T>
const boost::shared_ptr<internal::ExpressionNode<T> >& Expression<T>::root() const {
return root_;
}
template<typename T>
size_t Expression<T>::traceSize() const {
return root_->traceSize();
}
// Private methods:
template<typename T>
T Expression<T>::valueAndDerivatives(const Values& values,
const KeyVector& keys, const FastVector<int>& dims,
std::vector<Matrix>& H) const {
// H should be pre-allocated
assert(H.size()==keys.size());
// Pre-allocate and zero VerticalBlockMatrix
static const int Dim = traits<T>::dimension;
VerticalBlockMatrix Ab(dims, Dim);
Ab.matrix().setZero();
internal::JacobianMap jacobianMap(keys, Ab);
// Call unsafe version
T result = valueAndJacobianMap(values, jacobianMap);
// Copy blocks into the vector of jacobians passed in
for (DenseIndex i = 0; i < static_cast<DenseIndex>(keys.size()); i++)
H[i] = Ab(i);
return result;
}
template<typename T>
T Expression<T>::traceExecution(const Values& values,
internal::ExecutionTrace<T>& trace, void* traceStorage) const {
return root_->traceExecution(values, trace,
static_cast<internal::ExecutionTraceStorage*>(traceStorage));
}
template<typename T>
T Expression<T>::valueAndJacobianMap(const Values& values,
internal::JacobianMap& jacobians) const {
// The following piece of code is absolutely crucial for performance.
// We allocate a block of memory on the stack, which can be done at runtime
// with modern C++ compilers. The traceExecution then fills this memory
// with an execution trace, made up entirely of "Record" structs, see
// the FunctionalNode class in expression-inl.h
size_t size = traceSize();
// Windows does not support variable length arrays, so memory must be dynamically
// allocated on Visual Studio. For more information see the issue below
// https://bitbucket.org/gtborg/gtsam/issue/178/vlas-unsupported-in-visual-studio
#ifdef _MSC_VER
internal::ExecutionTraceStorage* traceStorage = new internal::ExecutionTraceStorage[size];
#else
internal::ExecutionTraceStorage traceStorage[size];
#endif
internal::ExecutionTrace<T> trace;
T value(this->traceExecution(values, trace, traceStorage));
trace.startReverseAD1(jacobians);
#ifdef _MSC_VER
delete[] traceStorage;
#endif
return value;
}
template<typename T>
typename Expression<T>::KeysAndDims Expression<T>::keysAndDims() const {
std::map<Key, int> map;
dims(map);
size_t n = map.size();
KeysAndDims pair = std::make_pair(KeyVector(n), FastVector<int>(n));
boost::copy(map | boost::adaptors::map_keys, pair.first.begin());
boost::copy(map | boost::adaptors::map_values, pair.second.begin());
return pair;
}
namespace internal {
// http://stackoverflow.com/questions/16260445/boost-bind-to-operator
template<class T>
struct apply_compose {
typedef T result_type;
static const int Dim = traits<T>::dimension;
T operator()(const T& x, const T& y, OptionalJacobian<Dim, Dim> H1 =
boost::none, OptionalJacobian<Dim, Dim> H2 = boost::none) const {
return x.compose(y, H1, H2);
}
};
}
// Global methods:
/// Construct a product expression, assumes T::compose(T) -> T
template<typename T>
Expression<T> operator*(const Expression<T>& expression1,
const Expression<T>& expression2) {
return Expression<T>(
boost::bind(internal::apply_compose<T>(), _1, _2, _3, _4), expression1,
expression2);
}
/// Construct an array of leaves
template<typename T>
std::vector<Expression<T> > createUnknowns(size_t n, char c, size_t start) {
std::vector<Expression<T> > unknowns;
unknowns.reserve(n);
for (size_t i = start; i < start + n; i++)
unknowns.push_back(Expression<T>(c, i));
return unknowns;
}
template <typename T>
ScalarMultiplyExpression<T>::ScalarMultiplyExpression(double s, const Expression<T>& e)
: Expression<T>(boost::make_shared<internal::ScalarMultiplyNode<T>>(s, e)) {}
template <typename T>
SumExpression<T>::SumExpression(const std::vector<Expression<T>>& expressions)
: Expression<T>(boost::make_shared<internal::SumExpressionNode<T>>(expressions)) {}
template <typename T>
SumExpression<T> SumExpression<T>::operator+(const Expression<T>& e) const {
SumExpression<T> copy = *this;
boost::static_pointer_cast<internal::SumExpressionNode<T>>(copy.root_)->add(e);
return copy;
}
template <typename T>
SumExpression<T>& SumExpression<T>::operator+=(const Expression<T>& e) {
boost::static_pointer_cast<internal::SumExpressionNode<T>>(this->root_)->add(e);
return *this;
}
template <typename T>
size_t SumExpression<T>::nrTerms() const {
return boost::static_pointer_cast<internal::SumExpressionNode<T>>(this->root_)->nrTerms();
}
} // namespace gtsam