InferTree.cpp

#include "InferTree.h"
#include "GraphPairwise.h"

namespace DirectGraphicalModels
{
void CInferTree::calculateMessages(unsigned int)
{
    byte    nStates = getGraph().getNumStates();
    size_t  nNodes  = getGraph().getNumNodes();

    // ====================================== Initialization ======================================
    for (ptr_edge_t &edge: getGraphPairwise().m_vEdges) {
        delete[] edge->msg;
        edge->msg = NULL;
        edge->suspend = false;
    }

    // =================================== Computing messages ===================================   
    size_t  * nFromEdges = new size_t[nNodes];                          // Count number of neighbors
    std::deque<size_t> nodeQueue;
    for (ptr_node_t &node: getGraphPairwise().m_vNodes) {
        nFromEdges[node->id] = node->from.size();                       // number of incoming edges
        if (nFromEdges[node->id] <= 1) nodeQueue.push_back(node->id);   // Add all leafs to the queue
    }


    float *temp = new float[nStates];
    while (!nodeQueue.empty()) {
        //for (size_t q = 0; q < nodeQueue.size(); q++) printf("%d, ", nodeQueue[q]);   printf("\n");
            
        size_t n = nodeQueue.front();                   // n - node with one neighbour
        nodeQueue.pop_front();

        Node  *node     = getGraphPairwise().m_vNodes[n].get(); // Node with one neighbour
        size_t nToEdges = node->to.size();
            
        bool allSuspend = true;
        for (size_t e_t = 0; e_t < nToEdges; e_t++) {
            Edge *edge_to = getGraphPairwise().m_vEdges[node->to[e_t]].get();
            if (!edge_to->suspend) {
                allSuspend = false;
                break;
            }
        }

        if (allSuspend) {   // Now prepare messages for suspending edges
            for (size_t e_t = 0; e_t < nToEdges; e_t++) {
                Edge *edge_to = getGraphPairwise().m_vEdges[node->to[e_t]].get();
                if (edge_to->msg) continue;
                    
                calculateMessage(edge_to, temp, edge_to->msg);
                    
                size_t n2 = edge_to->node2;
                nFromEdges[n2]--;
                if (nFromEdges[n2] <= 1) nodeQueue.push_back(n2);
            }
        } else {            // Prepare messages for all non-suspending edges    
            for (size_t e_t = 0; e_t < nToEdges; e_t++) {
                Edge * edge_to = getGraphPairwise().m_vEdges[node->to[e_t]].get();
                if (edge_to->suspend) continue;
                if (edge_to->msg)     continue;
                    
                calculateMessage(edge_to, temp, edge_to->msg);
                    
                size_t n2 = edge_to->node2;
                nFromEdges[n2]--;
                if (nFromEdges[n2] <= 1) nodeQueue.push_back(n2);
            }
        }
    } // while

    delete[] temp;
    delete[] nFromEdges;
}
}