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Changed order of conditionals created during elimination. Added unit test for disconnected graphs

release/4.3a0
Richard Roberts 2013-06-06 15:36:13 +00:00
parent 9bd7af848c
commit 7dfd999673
2 changed files with 34 additions and 23 deletions
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17
gtsam/inference/EliminationTreeUnordered-inl.h
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@ -175,11 +175,7 @@ namespace gtsam {
EliminationTreeUnordered<BAYESNET,GRAPH>::eliminate(Eliminate function) const EliminationTreeUnordered<BAYESNET,GRAPH>::eliminate(Eliminate function) const
{ {
// Stack for eliminating nodes. We use this stack instead of recursive function calls to // Stack for eliminating nodes. We use this stack instead of recursive function calls to
// avoid call stack overflow due to very long trees that arise from chain-like graphs. We use // avoid call stack overflow due to very long trees that arise from chain-like graphs.
// an std::vector for storage here since we do not want frequent reallocations and do not care
// about the vector growing to be very large once and not being deallocated until this
// function exits, because in the worst case we only store one pointer in this stack for each
// variable in the system.
// TODO: Check whether this is faster as a vector (then use indices instead of parent pointers). // TODO: Check whether this is faster as a vector (then use indices instead of parent pointers).
typedef EliminationNode<This> EliminationNode; typedef EliminationNode<This> EliminationNode;
std::stack<EliminationNode, FastList<EliminationNode> > eliminationStack; std::stack<EliminationNode, FastList<EliminationNode> > eliminationStack;
@ -192,8 +188,9 @@ namespace gtsam {
boost::shared_ptr<FactorGraphType> remainingFactors = boost::shared_ptr<FactorGraphType> remainingFactors =
boost::make_shared<FactorGraphType>(remainingFactors_.begin(), remainingFactors_.end()); boost::make_shared<FactorGraphType>(remainingFactors_.begin(), remainingFactors_.end());
// Add roots to the stack // Add roots to the stack (use reverse foreach so conditionals to appear in elimination order -
BOOST_FOREACH(const sharedNode& root, roots_) { // doesn't matter for computation but can make printouts easier to interpret by hand)
BOOST_REVERSE_FOREACH(const sharedNode& root, roots_) {
eliminationStack.push( eliminationStack.push(
EliminationNode(root.get(), root->factors.size() + root->subTrees.size(), EliminationNode(root.get(), root->factors.size() + root->subTrees.size(),
root->factors.begin(), root->factors.end(), 0)); } root->factors.begin(), root->factors.end(), 0)); }
@ -221,9 +218,11 @@ namespace gtsam {
// Remove from stack // Remove from stack
eliminationStack.pop(); eliminationStack.pop();
} else { } else {
// Expand children and mark as expanded // Expand children and mark as expanded (use reverse foreach so conditionals to appear in
// elimination order - doesn't matter for computation but can make printouts easier to
// interpret by hand)
node.expanded = true; node.expanded = true;
BOOST_FOREACH(const sharedNode& child, node.treeNode->subTrees) { BOOST_REVERSE_FOREACH(const sharedNode& child, node.treeNode->subTrees) {
eliminationStack.push( eliminationStack.push(
EliminationNode(child.get(), child->factors.size() + child->subTrees.size(), EliminationNode(child.get(), child->factors.size() + child->subTrees.size(),
child->factors.begin(), child->factors.end(), &node)); } child->factors.begin(), child->factors.end(), &node)); }

40
gtsam/symbolic/tests/testSymbolicEliminationTree.cpp
View File

@ -90,11 +90,11 @@ TEST_UNSAFE(EliminationTree, eliminate )
{ {
// create expected Chordal bayes Net // create expected Chordal bayes Net
SymbolicBayesNetUnordered expected; SymbolicBayesNetUnordered expected;
expected.push_back(boost::make_shared<SymbolicConditionalUnordered>(4));
expected.push_back(boost::make_shared<SymbolicConditionalUnordered>(3,4));
expected.push_back(boost::make_shared<SymbolicConditionalUnordered>(2,4));
expected.push_back(boost::make_shared<SymbolicConditionalUnordered>(1,2,4));
expected.push_back(boost::make_shared<SymbolicConditionalUnordered>(0,1,2)); expected.push_back(boost::make_shared<SymbolicConditionalUnordered>(0,1,2));
expected.push_back(boost::make_shared<SymbolicConditionalUnordered>(1,2,4));
expected.push_back(boost::make_shared<SymbolicConditionalUnordered>(2,4));
expected.push_back(boost::make_shared<SymbolicConditionalUnordered>(3,4));
expected.push_back(boost::make_shared<SymbolicConditionalUnordered>(4));
// Create factor graph // Create factor graph
SymbolicFactorGraphUnordered fg; SymbolicFactorGraphUnordered fg;
@ -109,19 +109,31 @@ TEST_UNSAFE(EliminationTree, eliminate )
order += 0,1,2,3,4; order += 0,1,2,3,4;
SymbolicBayesNetUnordered actual = *SymbolicEliminationTreeUnordered(fg,order).eliminate(EliminateSymbolicUnordered).first; SymbolicBayesNetUnordered actual = *SymbolicEliminationTreeUnordered(fg,order).eliminate(EliminateSymbolicUnordered).first;
CHECK(assert_equal(expected,actual)); EXPECT(assert_equal(expected,actual));
} }
/* ************************************************************************* */ /* ************************************************************************* */
//TEST(EliminationTree, disconnected_graph) { TEST(EliminationTree, disconnected_graph) {
// SymbolicFactorGraph fg; SymbolicFactorGraphUnordered fg;
// fg.push_factor(0, 1); fg.push_factor(0, 1);
// fg.push_factor(0, 2); fg.push_factor(0, 2);
// fg.push_factor(1, 2); fg.push_factor(1, 2);
// fg.push_factor(3, 4); fg.push_factor(3, 4);
//
// CHECK_EXCEPTION(SymbolicEliminationTree::Create(fg), DisconnectedGraphException); // create expected Chordal bayes Net
//} SymbolicBayesNetUnordered expected;
expected.push_back(boost::make_shared<SymbolicConditionalUnordered>(0,1,2));
expected.push_back(boost::make_shared<SymbolicConditionalUnordered>(1,2));
expected.push_back(boost::make_shared<SymbolicConditionalUnordered>(2));
expected.push_back(boost::make_shared<SymbolicConditionalUnordered>(3,4));
expected.push_back(boost::make_shared<SymbolicConditionalUnordered>(4));
vector<size_t> order;
order += 0,1,2,3,4;
SymbolicBayesNetUnordered actual = *SymbolicEliminationTreeUnordered(fg, order).eliminate(EliminateSymbolicUnordered).first;
EXPECT(assert_equal(expected,actual));
}
/* ************************************************************************* */ /* ************************************************************************* */
int main() { int main() {