1 /* This file is part of libDAI - http://www.libdai.org/
2 *
4 * 2, or (at your option) any later version. libDAI is distributed without any
5 * warranty. See the file COPYING for more details.
6 *
7 * Copyright (C) 2009 Frederik Eaton [frederik at ofb dot net]
8 */
11 /// \file
12 /// \brief Defines class CBP [\ref EaG09]
13 /// \todo Improve documentation
16 #ifndef __defined_libdai_cbp_h
17 #define __defined_libdai_cbp_h
20 #include <fstream>
21 #include <boost/shared_ptr.hpp>
23 #include <dai/daialg.h>
24 #include <dai/cbp.h>
25 #include <dai/bbp.h>
28 namespace dai {
31 /// Find a variable to clamp using BBP (goes with maximum adjoint)
32 /// \see BBP
33 std::pair<size_t, size_t> bbpFindClampVar( const InfAlg &in_bp, bool clampingVar, const PropertySet &bbp_props, bbp_cfn_t cfn, Real *maxVarOut );
36 /// Class for CBP (Clamped Belief Propagation)
37 /** This algorithm uses configurable heuristics to choose a variable
38 * x_i and a state x_i*. Inference is done with x_i "clamped" to x_i*
39 * (i.e., conditional on x_i == x_i*), and also with the negation of this
40 * condition. Clamping is done recursively up to a fixed number of
41 * levels (other stopping criteria are also implemented, see
42 * \a recursion property). The resulting approximate marginals are
43 * combined using logZ estimates.
44 */
45 class CBP : public DAIAlgFG {
46 private:
47 /// Variable beliefs
48 std::vector<Factor> _beliefsV;
49 /// Factor beliefs
50 std::vector<Factor> _beliefsF;
51 /// Log-partition sum
52 double _logZ;
54 /// Counts number of clampings at each leaf node
55 double _sum_level;
57 /// Number of leaves of recursion tree
58 size_t _num_leaves;
60 /// Output stream where information about the clampings is written
61 boost::shared_ptr<std::ofstream> _clamp_ofstream;
63 /// Returns BBP cost function used
64 bbp_cfn_t BBP_cost_function() { return props.bbp_cfn; }
66 /// Prints beliefs, variables and partition sum, in case of a debugging build
67 void printDebugInfo();
69 /// Called by 'run', and by itself. Implements the main algorithm.
70 /** Chooses a variable to clamp, recurses, combines the logZ and
71 * beliefs estimates of the children, and returns the improved
72 * estimates in \a lz_out and \a beliefs_out to its parent
73 */
74 void runRecurse( InfAlg *bp, double orig_logZ, std::vector<size_t> clamped_vars_list, size_t &num_leaves,
75 size_t &choose_count, double &sum_level, Real &lz_out, std::vector<Factor> &beliefs_out );
77 /// Choose the next variable to clamp
78 /** Choose the next variable to clamp, given a converged InfAlg (\a bp),
79 * and a vector of variables that are already clamped (\a
80 * clamped_vars_list). Returns the chosen variable in \a i, and
81 * the set of states in \a xis. If \a maxVarOut is non-NULL and
82 * props.choose==CHOOSE_BBP then it is used to store the
83 * adjoint of the chosen variable
84 */
85 virtual bool chooseNextClampVar( InfAlg* bp, std::vector<size_t> &clamped_vars_list, size_t &i, std::vector<size_t> &xis, Real *maxVarOut );
87 /// Return the InfAlg to use at each step of the recursion.
88 /// \todo At present, only returns a BP instance
89 InfAlg* getInfAlg();
91 /// Numer of iterations needed
92 size_t _iters;
93 /// Maximum difference encountered so far
94 double _maxdiff;
96 /// Sets variable beliefs, factor beliefs and logZ
97 /** \param bs should be a concatenation of the variable beliefs followed by the factor beliefs
98 */
99 void setBeliefs( const std::vector<Factor> &bs, double logZ );
101 /// Constructor helper function
102 void construct();
104 public:
105 /// Construct CBP object from FactorGraph fg and PropertySet opts
106 CBP( const FactorGraph &fg, const PropertySet &opts ) : DAIAlgFG(fg) {
107 props.set( opts );
108 construct();
109 }
111 /// Name of this inference algorithm
112 static const char *Name;
114 /// @name General InfAlg interface
115 //@{
116 virtual CBP* clone() const { return new CBP(*this); }
117 virtual std::string identify() const { return std::string(Name) + props.toString(); }
118 virtual Factor belief (const Var &n) const { return _beliefsV[findVar(n)]; }
119 virtual Factor belief (const VarSet &) const { DAI_THROW(NOT_IMPLEMENTED); }
120 virtual std::vector<Factor> beliefs() const { return concat(_beliefsV, _beliefsF); }
121 virtual Real logZ() const { return _logZ; }
122 virtual void init() {};
123 virtual void init( const VarSet & ) {};
124 virtual double run();
125 virtual double maxDiff() const { return _maxdiff; }
126 virtual size_t Iterations() const { return _iters; }
127 //@}
129 Factor beliefV( size_t i ) const { return _beliefsV[i]; }
130 Factor beliefF( size_t I ) const { return _beliefsF[I]; }
132 //----------------------------------------------------------------
134 /// Parameters of this inference algorithm
135 /* PROPERTIES(props,CBP) {
136 /// Enumeration of possible update schedules
137 typedef BP::Properties::UpdateType UpdateType;
138 /// Enumeration of possible methods for deciding when to stop recursing
139 DAI_ENUM(RecurseType,REC_FIXED,REC_LOGZ,REC_BDIFF);
140 /// Enumeration of possible heuristics for choosing clamping variable
141 DAI_ENUM(ChooseMethodType,CHOOSE_RANDOM,CHOOSE_MAXENT,CHOOSE_BBP,CHOOSE_BP_L1,CHOOSE_BP_CFN);
142 /// Enumeration of possible clampings: variables or factors
143 DAI_ENUM(ClampType,CLAMP_VAR,CLAMP_FACTOR);
145 /// Verbosity
146 size_t verbose = 0;
148 /// Tolerance to use in BP
149 double tol;
150 /// Update style for BP
152 /// Maximum number of iterations for BP
153 size_t maxiter;
155 /// Tolerance to use for controlling recursion depth (\a recurse is REC_LOGZ or REC_BDIFF)
156 double rec_tol;
157 /// Maximum number of levels of recursion (\a recurse is REC_FIXED)
158 size_t max_levels = 10;
159 /// If choose==CHOOSE_BBP and maximum adjoint is less than this value, don't recurse
161 /// Heuristic for choosing clamping variable
162 ChooseMethodType choose;
163 /// Method for deciding when to stop recursing
164 RecurseType recursion;
165 /// Whether to clamp variables or factors
166 ClampType clamp;
167 /// Properties to pass to BBP
168 PropertySet bbp_props;
169 /// Cost function to use for BBP
170 bbp_cfn_t bbp_cfn;
171 /// Random seed
172 size_t rand_seed = 0;
174 /// If non-empty, write clamping choices to this file
175 std::string clamp_outfile = "";
176 }
177 */
178 /* {{{ GENERATED CODE: DO NOT EDIT. Created by
179 ./scripts/regenerate-properties include/dai/cbp.h src/cbp.cpp
180 */
181 struct Properties {
182 /// Enumeration of possible update schedules
183 typedef BP::Properties::UpdateType UpdateType;
184 /// Enumeration of possible methods for deciding when to stop recursing
185 DAI_ENUM(RecurseType,REC_FIXED,REC_LOGZ,REC_BDIFF);
186 /// Enumeration of possible heuristics for choosing clamping variable
187 DAI_ENUM(ChooseMethodType,CHOOSE_RANDOM,CHOOSE_MAXENT,CHOOSE_BBP,CHOOSE_BP_L1,CHOOSE_BP_CFN);
188 /// Enumeration of possible clampings: variables or factors
189 DAI_ENUM(ClampType,CLAMP_VAR,CLAMP_FACTOR);
190 /// Verbosity
191 size_t verbose;
192 /// Tolerance to use in BP
193 double tol;
194 /// Update style for BP
196 /// Maximum number of iterations for BP
197 size_t maxiter;
198 /// Tolerance to use for controlling recursion depth (\a recurse is REC_LOGZ or REC_BDIFF)
199 double rec_tol;
200 /// Maximum number of levels of recursion (\a recurse is REC_FIXED)
201 size_t max_levels;
202 /// If choose==CHOOSE_BBP and maximum adjoint is less than this value, don't recurse
204 /// Heuristic for choosing clamping variable
205 ChooseMethodType choose;
206 /// Method for deciding when to stop recursing
207 RecurseType recursion;
208 /// Whether to clamp variables or factors
209 ClampType clamp;
210 /// Properties to pass to BBP
211 PropertySet bbp_props;
212 /// Cost function to use for BBP
213 bbp_cfn_t bbp_cfn;
214 /// Random seed
215 size_t rand_seed;
216 /// If non-empty, write clamping choices to this file
217 std::string clamp_outfile;
219 /// Set members from PropertySet
220 void set(const PropertySet &opts);
221 /// Get members into PropertySet
222 PropertySet get() const;
223 /// Convert to a string which can be parsed as a PropertySet
224 std::string toString() const;
225 } props;
226 /* }}} END OF GENERATED CODE */
228 /// Returns heuristic used for clamping variable
229 Properties::ChooseMethodType ChooseMethod() { return props.choose; }
230 /// Returns method used for deciding when to stop recursing
231 Properties::RecurseType Recursion() { return props.recursion; }
232 /// Returns clamping type used
233 Properties::ClampType Clamping() { return props.clamp; }
234 /// Returns maximum number of levels of recursion
235 size_t maxClampLevel() { return props.max_levels; }
237 double minMaxAdj() { return props.min_max_adj; }
238 /// Returns tolerance used for controlling recursion depth
239 double recTol() { return props.rec_tol; }
240 };
243 /// Given a sorted vector of states \a xis and total state count \a n_states, return a vector of states not in \a xis
244 std::vector<size_t> complement( std::vector<size_t>& xis, size_t n_states );
246 /// Computes \f$\frac{\exp(a)}{\exp(a)+\exp(b)}\f$
247 Real unSoftMax( Real a, Real b );
249 /// Computes log of sum of exponents, i.e., \f$\log\left(\exp(a) + \exp(b)\right)\f$
250 Real logSumExp( Real a, Real b );
252 /// Compute sum of pairwise L-infinity distances of the first \a nv factors in each vector
253 Real dist( const std::vector<Factor>& b1, const std::vector<Factor>& b2, size_t nv );
256 } // end of namespace dai
259 #endif