-/* Copyright (C) 2009 Frederik Eaton [frederik at ofb dot net]
-
- This file is part of libDAI.
-
- libDAI is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
-
- libDAI is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with libDAI; if not, write to the Free Software
- Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
-*/
+/* This file is part of libDAI - http://www.libdai.org/
+ *
+ * libDAI is licensed under the terms of the GNU General Public License version
+ * 2, or (at your option) any later version. libDAI is distributed without any
+ * warranty. See the file COPYING for more details.
+ *
+ * Copyright (C) 2009 Frederik Eaton [frederik at ofb dot net]
+ */
/// \file
/// \brief Defines class BP_dual
-/// \todo Improve documentation
-/// \todo Clean up
+/// \todo This replicates a large part of the functionality of BP; would it not be shorter to adapt BP instead?
#ifndef __defined_libdai_bp_dual_h
namespace dai {
-/** Class to estimate "dual" versions of BP messages, and normalizers, given an InfAlg.
+/// Calculates both types of BP messages and their normalizers from an InfAlg.
+/** BP_dual calculates "dual" versions of BP messages (both messages from factors
+ * to variables and messages from variables to factors), and normalizers, given an InfAlg.
* These are computed from the variable and factor beliefs of the InfAlg.
* This class is used primarily by BBP.
*/
/// Groups together the data structures for storing the two types of messages and their normalizers
struct messages {
+ /// Unnormalized variable->factor messages
_edges_t<Prob> n;
+ /// Normalizers of variable->factor messages
_edges_t<Real> Zn;
+ /// Unnormalized Factor->variable messages
_edges_t<Prob> m;
+ /// Normalizers of factor->variable messages
_edges_t<Real> Zm;
};
+ /// Stores all messages
messages _msgs;
/// Groups together the data structures for storing the two types of beliefs and their normalizers
struct beliefs {
- // indexed by node
+ /// Unnormalized variable beliefs
std::vector<Prob> b1;
+ /// Normalizers of variable beliefs
std::vector<Real> Zb1;
- // indexed by factor
+ /// Unnormalized factor beliefs
std::vector<Prob> b2;
+ /// Normalizers of factor beliefs
std::vector<Real> Zb2;
};
+ /// Stores all beliefs
beliefs _beliefs;
+ /// Pointer to the InfAlg object
const InfAlg *_ia;
-
- void init();
+ /// Does all necessary preprocessing
+ void init();
+ /// Allocates space for _msgs
void regenerateMessages();
+ /// Allocates space for _beliefs
void regenerateBeliefs();
+ /// Calculate all messages from InfAlg beliefs
void calcMessages();
- void calcBeliefV(size_t i);
- void calcBeliefF(size_t I);
- void calcBeliefs();
-
+ /// Update factor->variable message (i->I)
void calcNewM(size_t i, size_t _I);
+ /// Update variable->factor message (I->i)
void calcNewN(size_t i, size_t _I);
+ /// Calculate all variable and factor beliefs from messages
+ void calcBeliefs();
+ /// Calculate variable belief
+ void calcBeliefV(size_t i);
+ /// Calculate factor belief
+ void calcBeliefF(size_t I);
+
public:
- /// Construct BP_dual object from (converged) InfAlg object's beliefs and factors.
- /* A pointer to the the InfAlg object is stored,
+ /// Construct BP_dual object from (converged) InfAlg object's beliefs and factors.
+ /* A pointer to the the InfAlg object is stored,
* so the object must not be destroyed before the BP_dual is destroyed.
*/
BP_dual( const InfAlg *ia ) : _ia(ia) { init(); }
+ /// Returns the underlying FactorGraph
const FactorGraph& fg() const { return _ia->fg(); }
- /// factor -> var message
- DAI_ACCMUT(Prob & msgM(size_t i, size_t _I), { return _msgs.m[i][_I]; });
- /// var -> factor message
- DAI_ACCMUT(Prob & msgN(size_t i, size_t _I), { return _msgs.n[i][_I]; });
- /// Normalizer for msgM
- DAI_ACCMUT(Real & zM(size_t i, size_t _I), { return _msgs.Zm[i][_I]; });
- /// Normalizer for msgN
- DAI_ACCMUT(Real & zN(size_t i, size_t _I), { return _msgs.Zn[i][_I]; });
-
- /// Variable belief
- Factor beliefV(size_t i) const { return Factor(_ia->fg().var(i), _beliefs.b1[i]); }
- /// Factor belief
- Factor beliefF(size_t I) const { return Factor(_ia->fg().factor(I).vars(), _beliefs.b2[I]); }
-
- /// Normalizer for variable belief
- Real beliefVZ(size_t i) const { return _beliefs.Zb1[i]; }
- /// Normalizer for factor belief
- Real beliefFZ(size_t I) const { return _beliefs.Zb2[I]; }
-
+ /// Returns factor -> var message (I->i)
+ DAI_ACCMUT(Prob & msgM( size_t i, size_t _I ), { return _msgs.m[i][_I]; });
+ /// Returns var -> factor message (i->I)
+ DAI_ACCMUT(Prob & msgN( size_t i, size_t _I ), { return _msgs.n[i][_I]; });
+ /// Returns normalizer for msgM
+ DAI_ACCMUT(Real & zM( size_t i, size_t _I ), { return _msgs.Zm[i][_I]; });
+ /// Returns normalizer for msgN
+ DAI_ACCMUT(Real & zN( size_t i, size_t _I ), { return _msgs.Zn[i][_I]; });
+
+ /// Returns variable belief
+ Factor beliefV( size_t i ) const { return Factor( _ia->fg().var(i), _beliefs.b1[i] ); }
+ /// Returns factor belief
+ Factor beliefF( size_t I ) const { return Factor( _ia->fg().factor(I).vars(), _beliefs.b2[I] ); }
+
+ /// Returns normalizer for variable belief
+ Real beliefVZ( size_t i ) const { return _beliefs.Zb1[i]; }
+ /// Returns normalizer for factor belief
+ Real beliefFZ( size_t I ) const { return _beliefs.Zb2[I]; }
};
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