void CRF::TreeBP(bool maximize)
{
messages = (double ***) R_allocArray<double>(2, nEdges, maxState);
for (int i = 0; i < nEdges; i++)
for (int j = 0; j < maxState; j++)
messages[0][i][j] = messages[1][i][j] = 1;
int *nWaiting = (int *) R_alloc(nNodes, sizeof(int));
int **waiting = (int **) R_allocArray2<int>(nNodes, nAdj);
int *sent = (int *) R_alloc(nNodes, sizeof(int));
int senderHead, senderTail, nReceiver;
int *sender = (int *) R_alloc(nNodes * 2, sizeof(int));
int *receiver = (int *) R_alloc(nNodes, sizeof(int));
double sumBel;
senderHead = senderTail = nReceiver = 0;
for (int i = 0; i < nNodes; i++)
{
nWaiting[i] = nAdj[i];
for (int j = 0; j < nAdj[i]; j++)
waiting[i][j] = 1;
sent[i] = -1;
if (nAdj[i] == 1)
sender[senderTail++] = i;
sumBel = 0;
for (int j = 0; j < nStates[i]; j++)
sumBel += NodeBel(i, j) = NodePot(i, j);
for (int j = 0; j < nStates[i]; j++)
NodeBel(i, j) /= sumBel;
}
int s, r, e, n;
double *msg;
double *outgoing = (double *) R_alloc(maxState, sizeof(double));
while (senderHead < senderTail)
{
R_CheckUserInterrupt();
s = sender[senderHead++];
if (sent[s] == -2) continue;
nReceiver = 0;
if (nWaiting[s] == 1)
{
for (int i = 0; i < nAdj[s]; i++)
{
if (waiting[s][i])
{
receiver[nReceiver++] = i;
sent[s] = nAdj[s] == 1 ? -2 : i;
break;
}
}
}
else
{
for (int i = 0; i < nAdj[s]; i++)
if (sent[s] != i)
receiver[nReceiver++] = i;
sent[s] = -2;
}
/* send messages */
for (int i = 0; i < nReceiver; i++)
{
n = receiver[i];
r = AdjNodes(s, n);
e = AdjEdges(s, n);
for (int j = 0; j < nAdj[r]; j++)
if (AdjNodes(r, j) == s)
{
waiting[r][j] = 0;
nWaiting[r]--;
break;
}
if (sent[r] != -2 && nWaiting[r] <= 1)
sender[senderTail++] = r;
if (maximize)
msg = ComputeMessagesMax(s, r, e, outgoing, messages, messages);
else
msg = ComputeMessagesSum(s, r, e, outgoing, messages, messages);
sumBel = 0;
for (int j = 0; j < nStates[r]; j++)
sumBel += NodeBel(r, j) *= msg[j];
for (int j = 0; j < nStates[r]; j++)
NodeBel(r, j) /= sumBel;
}
}
}
AdjEdges WingedVertex :: adjacentEdges (WingedEdge& e) const {
return AdjEdges (*this, e);
}