Exemple #1
0
size_t countLoops( const FactorGraph & fg, size_t loopdepth ) {
    set<VarSet> loops;
    for( vector<Var>::const_iterator i0 = fg.vars().begin(); i0 != fg.vars().end(); i0++ ) {
        VarSet i0d = fg.delta(*i0);
        if( loopdepth > 1 )
            findLoopClusters( fg, loops, *i0, *i0, loopdepth - 1, i0d );
    }
    return loops.size();
}
Exemple #2
0
void findLoopClusters( const FactorGraph & fg, std::set<VarSet> &allcl, VarSet newcl, const Var & root, size_t length, VarSet vars ) {
    for( VarSet::const_iterator in = vars.begin(); in != vars.end(); in++ ) {
        VarSet ind = fg.delta( *in );
        if( (newcl.size()) >= 2 && ind.contains( root ) ) {
            allcl.insert( newcl | *in );
        }
        else if( length > 1 )
            findLoopClusters( fg, allcl, newcl | *in, root, length - 1, ind / newcl );
    }
}
Exemple #3
0
int main( int argc, char *argv[] ) {
    if( argc != 3 ) {
        cout << "Usage: " << argv[0] << " <in.fg> <tw>" << endl << endl;
        cout << "Reports some characteristics of the .fg network." << endl;
        cout << "Also calculates treewidth (which may take some time) unless <tw> == 0." << endl;
        return 1;
    } else {
        // Read factorgraph
        FactorGraph fg;
        char *infile = argv[1];
        int calc_tw = atoi(argv[2]);
        fg.ReadFromFile( infile );

        cout << "Number of variables:   " << fg.nrVars() << endl;
        cout << "Number of factors:     " << fg.nrFactors() << endl;
        cout << "Connected:             " << fg.isConnected() << endl;
        cout << "Tree:                  " << fg.isTree() << endl;
        cout << "Has short loops:       " << hasShortLoops(fg.factors()) << endl;
        cout << "Has negatives:         " << hasNegatives(fg.factors()) << endl;
        cout << "Binary variables?      " << fg.isBinary() << endl;
        cout << "Pairwise interactions? " << fg.isPairwise() << endl;
        if( calc_tw ) {
            std::pair<size_t,size_t> tw = treewidth(fg);
            cout << "Treewidth:           " << tw.first << endl;
            cout << "Largest cluster for JTree has " << tw.second << " states " << endl;
        }
        double stsp = 1.0;
        for( size_t i = 0; i < fg.nrVars(); i++ )
            stsp *= fg.var(i).states();
        cout << "Total state space:   " << stsp << endl;

        double cavsum_lcbp = 0.0;
        double cavsum_lcbp2 = 0.0;
        size_t max_Delta_size = 0;
        map<size_t,size_t> cavsizes;
        for( size_t i = 0; i < fg.nrVars(); i++ ) {
            VarSet di = fg.delta(i);
            if( cavsizes.count(di.size()) )
                cavsizes[di.size()]++;
            else
                cavsizes[di.size()] = 1;
            size_t Ds = fg.Delta(i).nrStates();
            if( Ds > max_Delta_size )
                max_Delta_size = Ds;
            cavsum_lcbp += di.nrStates();
            for( VarSet::const_iterator j = di.begin(); j != di.end(); j++ )
                cavsum_lcbp2 += j->states();
        }
        cout << "Maximum pancake has " << max_Delta_size << " states" << endl;
        cout << "LCBP with full cavities needs " << cavsum_lcbp << " BP runs" << endl;
        cout << "LCBP with only pairinteractions needs " << cavsum_lcbp2 << " BP runs" << endl;
        cout << "Cavity sizes: ";
        for( map<size_t,size_t>::const_iterator it = cavsizes.begin(); it != cavsizes.end(); it++ ) 
            cout << it->first << "(" << it->second << ") ";
        cout << endl;

        cout << "Type: " << (fg.isPairwise() ? "pairwise" : "higher order") << " interactions, " << (fg.isBinary() ? "binary" : "nonbinary") << " variables" << endl;

        if( fg.isPairwise() ) {
            bool girth_reached = false;
            size_t loopdepth;
            for( loopdepth = 2; loopdepth <= fg.nrVars() && !girth_reached; loopdepth++ ) {
                size_t nr_loops = countLoops( fg, loopdepth );
                cout << "Loops up to " << loopdepth << " variables: " << nr_loops << endl;
                if( nr_loops > 0 )
                    girth_reached = true;
            }
            if( girth_reached )
                cout << "Girth: " << loopdepth-1 << endl;
            else
                cout << "Girth: infinity" << endl;
        }

        return 0;
    }
}