253 lines
		
	
	
		
			8.9 KiB
		
	
	
	
		
			C++
		
	
	
			
		
		
	
	
			253 lines
		
	
	
		
			8.9 KiB
		
	
	
	
		
			C++
		
	
	
| /**
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|  * @file   FactorGraph-inl.h
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|  * This is a template definition file, include it where needed (only!)
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|  * so that the appropriate code is generated and link errors avoided.
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|  * @brief  Factor Graph Base Class
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|  * @author Carlos Nieto
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|  * @author Frank Dellaert
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|  * @author Alireza Fathi
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|  */
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| 
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| #pragma once
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| 
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| #include <list>
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| #include <sstream>
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| #include <stdexcept>
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| #include <functional>
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| 
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| #include <boost/foreach.hpp>
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| #include <boost/tuple/tuple.hpp>
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| #include <colamd/colamd.h>
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| #include "Ordering.h"
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| #include "FactorGraph.h"
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| 
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| // trick from some reading group
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| #define FOREACH_PAIR( KEY, VAL, COL) BOOST_FOREACH (boost::tie(KEY,VAL),COL)
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| 
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| using namespace std;
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| 
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| namespace gtsam {
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| 
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| /* ************************************************************************* */
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| template<class Factor>
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| template<class Conditional>
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| FactorGraph<Factor>::FactorGraph(const BayesNet<Conditional>& bayesNet)
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| {
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| 	typename BayesNet<Conditional>::const_iterator it = bayesNet.begin();
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| 	for(; it != bayesNet.end(); it++) {
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| 		sharedFactor factor(new Factor(*it));
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| 		push_back(factor);
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| 	}
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| }
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| 
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| /* ************************************************************************* */
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| template<class Factor>
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| void FactorGraph<Factor>::print(const string& s) const {
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| 	cout << s << endl;
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| 	printf("size: %d\n", (int) size());
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| 	for (int i = 0; i < factors_.size(); i++) {
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| 		stringstream ss;
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| 		ss << "factor " << i << ":";
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| 		if (factors_[i] != NULL) factors_[i]->print(ss.str());
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| 	}
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| }
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| 
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| /* ************************************************************************* */
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| template<class Factor>
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| bool FactorGraph<Factor>::equals
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| 	(const FactorGraph<Factor>& fg, double tol) const {
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| 	/** check whether the two factor graphs have the same number of factors_ */
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| 	if (factors_.size() != fg.size()) return false;
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| 
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| 	/** check whether the factors_ are the same */
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| 	for (size_t i = 0; i < factors_.size(); i++) {
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| 		// TODO: Doesn't this force order of factor insertion?
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| 		sharedFactor f1 = factors_[i], f2 = fg.factors_[i];
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| 		if (f1 == NULL && f2 == NULL) continue;
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| 		if (f1 == NULL || f2 == NULL) return false;
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| 		if (!f1->equals(*f2, tol)) return false;
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| 	}
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| 	return true;
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| }
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| 
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| /* ************************************************************************* */
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| template<class Factor>
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| size_t FactorGraph<Factor>::nrFactors() const {
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| 	int size_ = 0;
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| 	for (const_iterator factor = factors_.begin(); factor != factors_.end(); factor++)
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| 		if (*factor != NULL) size_++;
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| 	return size_;
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| }
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| 
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| /* ************************************************************************* */
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| template<class Factor>
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| void FactorGraph<Factor>::push_back(sharedFactor factor) {
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| 	factors_.push_back(factor);                  // add the actual factor
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| 	if (factor==NULL) return;
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| 
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| 	int i = factors_.size() - 1;                 // index of factor
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| 	list<string> keys = factor->keys();          // get keys for factor
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| 
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| 	BOOST_FOREACH(string key, keys){             // for each key push i onto list
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| 		Indices::iterator it = indices_.find(key); // old list for that key (if exists)
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| 		if (it==indices_.end()){                   // there's no list yet
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| 			list<int> indices(1,i);                  // so make one
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| 			indices_.insert(make_pair(key,indices)); // insert new indices into factorMap
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| 		}
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| 		else {
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| 			list<int> *indices_ptr = &(it->second);  // get the list
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| 			indices_ptr->push_back(i);               // add the index i to it
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| 		}
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| 	}
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| }
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| 
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| /* ************************************************************************* */
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| template<class Factor>
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| void FactorGraph<Factor>::push_back(const FactorGraph<Factor>& factors) {
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| 	const_iterator factor = factors.begin();
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| 	for (; factor!= factors.end(); factor++)
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| 		push_back(*factor);
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| }
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| 
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| /* ************************************************************************* */
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| template<class Factor>
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| Ordering FactorGraph<Factor>::keys() const {
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| 	Ordering keys;
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| 	transform(indices_.begin(), indices_.end(),
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| 			back_inserter(keys), _Select1st<Indices::value_type>());
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| 	return keys;
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| }
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| 
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| /* ************************************************************************* */
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| /**
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|  * Call colamd given a column-major symbolic matrix A
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|  * @param n_col colamd arg 1: number of rows in A
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|  * @param n_row colamd arg 2: number of columns in A
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|  * @param nrNonZeros number of non-zero entries in A
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|  * @param columns map from keys to a sparse column of non-zero row indices
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|  */
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| template <class Key>
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| Ordering colamd(int n_col, int n_row, int nrNonZeros, const map<Key, vector<int> >& columns) {
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| 
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| 	// Convert to compressed column major format colamd wants it in (== MATLAB format!)
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| 	vector<Key> initialOrder;
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| 	int Alen = nrNonZeros*30;     /* colamd arg 3: size of the array A TODO: use Tim's function ! */
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| 	int * A = new int[Alen];      /* colamd arg 4: row indices of A, of size Alen */
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| 	int * p = new int[n_col + 1]; /* colamd arg 5: column pointers of A, of size n_col+1 */
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| 
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| 	p[0] = 0;
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| 	int j = 1;
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| 	int count = 0;
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| 	typedef typename map<Key, vector<int> >::const_iterator iterator;
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| 	for(iterator it = columns.begin(); it != columns.end(); it++) {
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| 		const Key& key = it->first;
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| 		const vector<int>& column = it->second;
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| 		initialOrder.push_back(key);
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| 		BOOST_FOREACH(int i, column) A[count++] = i; // copy sparse column
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| 		p[j] = count; // column j (base 1) goes from A[j-1] to A[j]-1
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| 		j+=1;
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| 	}
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| 
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| 	double* knobs = NULL;    /* colamd arg 6: parameters (uses defaults if NULL) */
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| 	int stats[COLAMD_STATS]; /* colamd arg 7: colamd output statistics and error codes */
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| 
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| 	// call colamd, result will be in p *************************************************
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| 	/* TODO: returns (1) if successful, (0) otherwise*/
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| 	::colamd(n_row, n_col, Alen, A, p, knobs, stats);
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| 	// **********************************************************************************
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| 	delete [] A; // delete symbolic A
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| 
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| 	// Convert elimination ordering in p to an ordering
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| 	Ordering result;
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| 	for(int j = 0; j < n_col; j++)
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| 		result.push_back(initialOrder[j]);
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| 	delete [] p; // delete colamd result vector
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| 
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| 	return result;
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| }
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| 
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| /* ************************************************************************* */
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| template<class Factor>
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| Ordering FactorGraph<Factor>::getOrdering() const {
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| 
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| 	// A factor graph is really laid out in row-major format, each factor a row
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| 	// Below, we compute a symbolic matrix stored in sparse columns.
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| 	typedef string Key;             // default case  with string keys
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| 	map<Key, vector<int> > columns; // map from keys to a sparse column of non-zero row indices
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| 	int nrNonZeros = 0;             // number of non-zero entries
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| 	int n_row = factors_.size();    /* colamd arg 1: number of rows in A */
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| 
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| 	// loop over all factors = rows
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| 	for (int i = 0; i < n_row; i++) {
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| 		if (factors_[i]==NULL) continue;
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| 		list<Key> keys = factors_[i]->keys();
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| 		BOOST_FOREACH(Key key, keys) columns[key].push_back(i);
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| 		nrNonZeros+= keys.size();
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| 	}
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| 	int n_col = (int)(columns.size()); /* colamd arg 2: number of columns in A */
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| 
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| 	if(n_col == 0)
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| 		return Ordering(); // empty ordering
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| 	else
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| 		return colamd(n_col, n_row, nrNonZeros, columns);
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| }
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| 
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| /* ************************************************************************* */
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| /** O(1)                                                                     */
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| /* ************************************************************************* */
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| template<class Factor>
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| list<int> FactorGraph<Factor>::factors(const string& key) const {
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| 	Indices::const_iterator it = indices_.find(key);
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| 	return it->second;
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| }
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| 
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| /* ************************************************************************* */
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| /** find all non-NULL factors for a variable, then set factors to NULL       */
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| /* ************************************************************************* */
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| template<class Factor>
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| vector<boost::shared_ptr<Factor> >
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| FactorGraph<Factor>::findAndRemoveFactors(const string& key) {
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| 	vector<sharedFactor> found;
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| 
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| 	Indices::iterator it = indices_.find(key);
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| 	if (it == indices_.end())
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| 		throw(invalid_argument
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| 				("FactorGraph::findAndRemoveFactors invalid key: " + key));
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| 
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| 	list<int> *indices_ptr; // pointer to indices list in indices_ map
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| 	indices_ptr = &(it->second);
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| 
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| 	BOOST_FOREACH(int i, *indices_ptr) {
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| 		if(factors_[i] == NULL) continue; // skip NULL factors
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| 		found.push_back(factors_[i]);     // add to found
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| 		factors_[i].reset();              // set factor to NULL.
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| 	}
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| 	return found;
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| }
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| 
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| /* ************************************************************************* */
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| /* find factors and remove them from the factor graph: O(n)                  */
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| /* ************************************************************************* */
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| template<class Factor> boost::shared_ptr<Factor>
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| removeAndCombineFactors(FactorGraph<Factor>& factorGraph, const string& key)
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| {
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| 	vector<boost::shared_ptr<Factor> > found = factorGraph.findAndRemoveFactors(key);
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| 	boost::shared_ptr<Factor> new_factor(new Factor(found));
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| 	return new_factor;
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| }
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| 
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| /* ************************************************************************* */
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| template<class Factor>
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| FactorGraph<Factor> combine(const FactorGraph<Factor>& fg1, const FactorGraph<Factor>& fg2) {
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| 	// create new linear factor graph equal to the first one
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| 	FactorGraph<Factor> fg = fg1;
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| 
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| 	// add the second factors_ in the graph
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| 	fg.push_back(fg2);
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| 
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| 	return fg;
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| }
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| 
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| /* ************************************************************************* */
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| }
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