public void forwardIBD() {
int numNodes = treeModel.getNodeCount();
int stateCount = substitutionModel.getStateCount();
getDiagonalRates(diag);
for (int nodeId = 0; nodeId < numNodes; ++nodeId) {
NodeRef node = treeModel.getNode(nodeId);
NodeRef parent = treeModel.getParent(node);
if (parent == null) { // handle the root
} else if (treeModel.isExternal(node)) { // Handle the tip
double branchTime =
branchRateModel.getBranchRate(treeModel, node)
* (treeModel.getNodeHeight(parent) - treeModel.getNodeHeight(node));
for (int state = 0; state < stateCount; ++state) {
ibdForward[nodeId][state] = Math.exp(-diag[state] * branchTime);
}
} else { // Handle internal node
double branchTime =
branchRateModel.getBranchRate(treeModel, node)
* (treeModel.getNodeHeight(parent) - treeModel.getNodeHeight(node));
int childCount = treeModel.getChildCount(node);
for (int state = 0; state < stateCount; ++state) {
ibdForward[nodeId][state] = 0;
for (int child = 0; child < childCount; ++child) {
int childNodeId = treeModel.getChild(node, child).getNumber();
ibdForward[nodeId][state] += ibdForward[childNodeId][state];
}
ibdForward[nodeId][state] *= Math.exp(-diag[state] * branchTime);
}
}
}
}
public void backwardIBD(NodeRef node) {
int stateCount = substitutionModel.getStateCount();
if (node == null) {
node = treeModel.getRoot();
int nodeId = node.getNumber();
for (int state = 0; state < stateCount; ++state) {
ibdBackward[nodeId][state] = 0;
}
}
getDiagonalRates(diag);
int childCount = treeModel.getChildCount(node);
int nodeId = node.getNumber();
for (int child = 0; child < childCount; ++child) {
NodeRef childNode = treeModel.getChild(node, child);
int childNodeId = childNode.getNumber();
double branchTime =
branchRateModel.getBranchRate(treeModel, childNode)
* (treeModel.getNodeHeight(node) - treeModel.getNodeHeight(childNode));
for (int state = 0; state < stateCount; ++state) {
ibdBackward[childNodeId][state] = ibdBackward[nodeId][state];
for (int sibling = 0; sibling < childCount; ++sibling) {
if (sibling != child) {
int siblingId = treeModel.getChild(node, sibling).getNumber();
ibdBackward[childNodeId][state] += ibdForward[siblingId][state];
}
}
ibdBackward[childNodeId][state] *= Math.exp(-diag[state] * branchTime);
}
}
for (int child = 0; child < childCount; ++child) {
NodeRef childNode = treeModel.getChild(node, child);
backwardIBD(childNode);
}
}