Super-speedup by specializing to 2-dimensional output (for now). Using some template magic.

release/4.3a0
dellaert 2014-10-08 23:50:17 +02:00
parent 31c138d0d6
commit 9ebe1e6d10
3 changed files with 100 additions and 38 deletions

View File

@ -33,7 +33,12 @@ typedef std::map<Key, Matrix> JacobianMap;
//-----------------------------------------------------------------------------
/// The JacobinaTrace class records a tree-structured expression's execution
template<class T>
struct JacobianTrace {
// Some fixed matrix sizes we need
typedef Eigen::Matrix<double, 2, T::dimension> Jacobian2T;
/**
* The Pointer class is a tagged union that obviates the need to create
* a JacobianTrace subclass for Constants and Leaf Expressions. Instead
@ -70,7 +75,6 @@ struct JacobianTrace {
content.ptr = trace;
}
// Either insert identity into Jacobians (Leaf) or propagate (Function)
template<class T>
void reverseAD(JacobianMap& jacobians) const {
if (type == Leaf) {
size_t n = T::Dim();
@ -89,17 +93,45 @@ struct JacobianTrace {
} else if (type == Function)
content.ptr->reverseAD(dTdA, jacobians);
}
// Either add to Jacobians (Leaf) or propagate (Function)
void reverseAD2(const Jacobian2T& dTdA, JacobianMap& jacobians) const {
if (type == Leaf) {
JacobianMap::iterator it = jacobians.find(content.key);
if (it != jacobians.end())
it->second += dTdA;
else
jacobians[content.key] = dTdA;
} else if (type == Function)
content.ptr->reverseAD2(dTdA, jacobians);
}
};
/// Make sure destructor is virtual
virtual ~JacobianTrace() {
}
virtual void reverseAD(JacobianMap& jacobians) const = 0;
virtual void reverseAD(const Matrix& dFdT, JacobianMap& jacobians) const = 0;
// template<class JacobianFT>
// void reverseAD(const JacobianFT& dFdT, JacobianMap& jacobians) const {
virtual void reverseAD2(const Jacobian2T& dFdT,
JacobianMap& jacobians) const = 0;
};
typedef JacobianTrace::Pointer TracePtr;
template<size_t M, class A>
struct Select {
typedef Eigen::Matrix<double, M, A::dimension> Jacobian;
static void reverseAD(const typename JacobianTrace<A>::Pointer& trace,
const Jacobian& dTdA, JacobianMap& jacobians) {
trace.reverseAD(dTdA, jacobians);
}
};
template<class A>
struct Select<2, A> {
typedef Eigen::Matrix<double, 2, A::dimension> Jacobian;
static void reverseAD(const typename JacobianTrace<A>::Pointer& trace,
const Jacobian& dTdA, JacobianMap& jacobians) {
trace.reverseAD2(dTdA, jacobians);
}
};
//template <class Derived>
//struct TypedTrace {
@ -243,7 +275,8 @@ public:
virtual Augmented<T> forward(const Values& values) const = 0;
/// Construct an execution trace for reverse AD
virtual T traceExecution(const Values& values, TracePtr& p) const = 0;
virtual T traceExecution(const Values& values,
typename JacobianTrace<T>::Pointer& p) const = 0;
};
//-----------------------------------------------------------------------------
@ -280,7 +313,8 @@ public:
}
/// Construct an execution trace for reverse AD
virtual T traceExecution(const Values& values, TracePtr& p) const {
virtual T traceExecution(const Values& values,
typename JacobianTrace<T>::Pointer& p) const {
return constant_;
}
};
@ -320,7 +354,8 @@ public:
}
/// Construct an execution trace for reverse AD
virtual T traceExecution(const Values& values, TracePtr& p) const {
virtual T traceExecution(const Values& values,
typename JacobianTrace<T>::Pointer& p) const {
p.setLeaf(key_);
return values.at<T>(key_);
}
@ -329,22 +364,22 @@ public:
//-----------------------------------------------------------------------------
/// Unary Function Expression
template<class T, class A>
template<class T, class A1>
class UnaryExpression: public ExpressionNode<T> {
public:
typedef Eigen::Matrix<double, T::dimension, A::dimension> JacobianTA;
typedef boost::function<T(const A&, boost::optional<JacobianTA&>)> Function;
typedef Eigen::Matrix<double, T::dimension, A1::dimension> JacobianTA;
typedef boost::function<T(const A1&, boost::optional<JacobianTA&>)> Function;
private:
Function function_;
boost::shared_ptr<ExpressionNode<A> > expressionA_;
boost::shared_ptr<ExpressionNode<A1> > expressionA1_;
/// Constructor with a unary function f, and input argument e
UnaryExpression(Function f, const Expression<A>& e) :
function_(f), expressionA_(e.root()) {
UnaryExpression(Function f, const Expression<A1>& e) :
function_(f), expressionA1_(e.root()) {
}
friend class Expression<T> ;
@ -353,18 +388,18 @@ public:
/// Return keys that play in this expression
virtual std::set<Key> keys() const {
return expressionA_->keys();
return expressionA1_->keys();
}
/// Return value
virtual T value(const Values& values) const {
return function_(this->expressionA_->value(values), boost::none);
return function_(this->expressionA1_->value(values), boost::none);
}
/// Return value and derivatives
virtual Augmented<T> forward(const Values& values) const {
using boost::none;
Augmented<A> argument = this->expressionA_->forward(values);
Augmented<A1> argument = this->expressionA1_->forward(values);
JacobianTA dTdA;
T t = function_(argument.value(),
argument.constant() ? none : boost::optional<JacobianTA&>(dTdA));
@ -372,26 +407,33 @@ public:
}
/// Trace structure for reverse AD
struct Trace: public JacobianTrace {
TracePtr trace;
JacobianTA dTdA;
struct Trace: public JacobianTrace<T> {
typename JacobianTrace<A1>::Pointer trace1;
JacobianTA dTdA1;
/// Start the reverse AD process
virtual void reverseAD(JacobianMap& jacobians) const {
trace.reverseAD(dTdA, jacobians);
Select<T::dimension, A1>::reverseAD(trace1, dTdA1, jacobians);
}
/// Given df/dT, multiply in dT/dA and continue reverse AD process
virtual void reverseAD(const Matrix& dFdT, JacobianMap& jacobians) const {
trace.reverseAD(dFdT * dTdA, jacobians);
trace1.reverseAD(dFdT * dTdA1, jacobians);
}
/// Version specialized to 2-dimensional output
typedef Eigen::Matrix<double, 2, T::dimension> Jacobian2T;
virtual void reverseAD2(const Jacobian2T& dFdT,
JacobianMap& jacobians) const {
trace1.reverseAD2(dFdT * dTdA1, jacobians);
}
};
/// Construct an execution trace for reverse AD
virtual T traceExecution(const Values& values, TracePtr& p) const {
virtual T traceExecution(const Values& values,
typename JacobianTrace<T>::Pointer& p) const {
Trace* trace = new Trace();
p.setFunction(trace);
A a = this->expressionA_->traceExecution(values, trace->trace);
return function_(a, trace->dTdA);
A1 a = this->expressionA1_->traceExecution(values, trace->trace1);
return function_(a, trace->dTdA1);
}
};
@ -454,25 +496,34 @@ public:
}
/// Trace structure for reverse AD
struct Trace: public JacobianTrace {
TracePtr trace1, trace2;
struct Trace: public JacobianTrace<T> {
typename JacobianTrace<A1>::Pointer trace1;
typename JacobianTrace<A2>::Pointer trace2;
JacobianTA1 dTdA1;
JacobianTA2 dTdA2;
/// Start the reverse AD process
virtual void reverseAD(JacobianMap& jacobians) const {
trace1.reverseAD(dTdA1, jacobians);
trace2.reverseAD(dTdA2, jacobians);
Select<T::dimension, A1>::reverseAD(trace1, dTdA1, jacobians);
Select<T::dimension, A2>::reverseAD(trace2, dTdA2, jacobians);
}
/// Given df/dT, multiply in dT/dA and continue reverse AD process
virtual void reverseAD(const Matrix& dFdT, JacobianMap& jacobians) const {
trace1.reverseAD(dFdT * dTdA1, jacobians);
trace2.reverseAD(dFdT * dTdA2, jacobians);
}
/// Version specialized to 2-dimensional output
typedef Eigen::Matrix<double, 2, T::dimension> Jacobian2T;
virtual void reverseAD2(const Jacobian2T& dFdT,
JacobianMap& jacobians) const {
trace1.reverseAD2(dFdT * dTdA1, jacobians);
trace2.reverseAD2(dFdT * dTdA2, jacobians);
}
};
/// Construct an execution trace for reverse AD
virtual T traceExecution(const Values& values, TracePtr& p) const {
virtual T traceExecution(const Values& values,
typename JacobianTrace<T>::Pointer& p) const {
Trace* trace = new Trace();
p.setFunction(trace);
A1 a1 = this->expressionA1_->traceExecution(values, trace->trace1);
@ -553,17 +604,19 @@ public:
}
/// Trace structure for reverse AD
struct Trace: public JacobianTrace {
TracePtr trace1, trace2, trace3;
struct Trace: public JacobianTrace<T> {
typename JacobianTrace<A1>::Pointer trace1;
typename JacobianTrace<A2>::Pointer trace2;
typename JacobianTrace<A3>::Pointer trace3;
JacobianTA1 dTdA1;
JacobianTA2 dTdA2;
JacobianTA3 dTdA3;
/// Start the reverse AD process
virtual void reverseAD(JacobianMap& jacobians) const {
trace1.reverseAD(dTdA1, jacobians);
trace2.reverseAD(dTdA2, jacobians);
trace3.reverseAD(dTdA3, jacobians);
Select<T::dimension, A1>::reverseAD(trace1, dTdA1, jacobians);
Select<T::dimension, A2>::reverseAD(trace2, dTdA2, jacobians);
Select<T::dimension, A3>::reverseAD(trace3, dTdA3, jacobians);
}
/// Given df/dT, multiply in dT/dA and continue reverse AD process
virtual void reverseAD(const Matrix& dFdT, JacobianMap& jacobians) const {
@ -571,10 +624,19 @@ public:
trace2.reverseAD(dFdT * dTdA2, jacobians);
trace3.reverseAD(dFdT * dTdA3, jacobians);
}
/// Version specialized to 2-dimensional output
typedef Eigen::Matrix<double, 2, T::dimension> Jacobian2T;
virtual void reverseAD2(const Jacobian2T& dFdT,
JacobianMap& jacobians) const {
trace1.reverseAD2(dFdT * dTdA1, jacobians);
trace2.reverseAD2(dFdT * dTdA2, jacobians);
trace3.reverseAD2(dFdT * dTdA3, jacobians);
}
};
/// Construct an execution trace for reverse AD
virtual T traceExecution(const Values& values, TracePtr& p) const {
virtual T traceExecution(const Values& values,
typename JacobianTrace<T>::Pointer& p) const {
Trace* trace = new Trace();
p.setFunction(trace);
A1 a1 = this->expressionA1_->traceExecution(values, trace->trace1);

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@ -117,10 +117,10 @@ public:
Augmented<T> augmented(const Values& values) const {
#define REVERSE_AD
#ifdef REVERSE_AD
JacobianTrace::Pointer pointer;
typename JacobianTrace<T>::Pointer pointer;
T value = root_->traceExecution(values,pointer);
Augmented<T> augmented(value);
pointer.reverseAD<T>(augmented.jacobians());
pointer.reverseAD(augmented.jacobians());
return augmented;
#else
return root_->forward(values);

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@ -81,7 +81,7 @@ TEST(Expression, leaf) {
TEST(Expression, test) {
// Test Constant expression
Expression<int> c(0);
Expression<Rot3> c(Rot3::identity());
// Create leaves
Expression<Pose3> x(1);