91 lines
2.7 KiB
C++
91 lines
2.7 KiB
C++
/*
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* BinaryAllDiff.h
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* @brief Binary "all-different" constraint
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* @date Feb 6, 2012
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* @author Frank Dellaert
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*/
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#pragma once
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#include <gtsam_unstable/discrete/Domain.h>
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#include <gtsam_unstable/discrete/Constraint.h>
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#include <gtsam/discrete/DecisionTreeFactor.h>
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namespace gtsam {
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/**
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* Binary AllDiff constraint
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* Returns 1 if values for two keys are different, 0 otherwise
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* DiscreteFactors are all awkward in that they have to store two types of keys:
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* for each variable we have a Index and an Index. In this factor, we
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* keep the Indices locally, and the Indices are stored in IndexFactor.
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*/
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class BinaryAllDiff: public Constraint {
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size_t cardinality0_, cardinality1_; /// cardinality
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public:
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/// Constructor
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BinaryAllDiff(const DiscreteKey& key1, const DiscreteKey& key2) :
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Constraint(key1.first, key2.first),
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cardinality0_(key1.second), cardinality1_(key2.second) {
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}
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// print
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virtual void print(const std::string& s = "",
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const IndexFormatter& formatter = DefaultIndexFormatter) const {
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std::cout << s << "BinaryAllDiff on " << formatter(keys_[0]) << " and "
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<< formatter(keys_[1]) << std::endl;
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}
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/// Calculate value
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virtual double operator()(const Values& values) const {
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return (double) (values.at(keys_[0]) != values.at(keys_[1]));
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}
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/// Convert into a decisiontree
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virtual DecisionTreeFactor toDecisionTreeFactor() const {
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DiscreteKeys keys;
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keys.push_back(DiscreteKey(keys_[0],cardinality0_));
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keys.push_back(DiscreteKey(keys_[1],cardinality1_));
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std::vector<double> table;
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for (size_t i1 = 0; i1 < cardinality0_; i1++)
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for (size_t i2 = 0; i2 < cardinality1_; i2++)
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table.push_back(i1 != i2);
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DecisionTreeFactor converted(keys, table);
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return converted;
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}
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/// Multiply into a decisiontree
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virtual DecisionTreeFactor operator*(const DecisionTreeFactor& f) const {
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// TODO: can we do this more efficiently?
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return toDecisionTreeFactor() * f;
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}
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/*
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* Ensure Arc-consistency
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* @param j domain to be checked
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* @param domains all other domains
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*/
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///
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bool ensureArcConsistency(size_t j, std::vector<Domain>& domains) const {
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// throw std::runtime_error(
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// "BinaryAllDiff::ensureArcConsistency not implemented");
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return false;
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}
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/// Partially apply known values
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virtual Constraint::shared_ptr partiallyApply(const Values&) const {
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throw std::runtime_error("BinaryAllDiff::partiallyApply not implemented");
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}
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/// Partially apply known values, domain version
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virtual Constraint::shared_ptr partiallyApply(
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const std::vector<Domain>&) const {
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throw std::runtime_error("BinaryAllDiff::partiallyApply not implemented");
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}
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};
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} // namespace gtsam
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