public RandomVariable calculate_next_backward_message(
RandomVariable forwardBelief, RandomVariable present_backward_message, String perception) {
RandomVariable result = present_backward_message.duplicate();
// System.out.println("fb :-calculating new backward message");
// System.out.println("fb :-diagonal matrix from sens model = ");
Matrix oMatrix = sensorModel.asMatrix(perception);
// System.out.println(oMatrix);
Matrix transitionMatrix = transitionModel.asMatrix(); // action
// should
// be
// passed
// in
// here?
// System.out.println("fb :-present backward message = "
// +present_backward_message);
Matrix backwardMatrix =
transitionMatrix.times(oMatrix.times(present_backward_message.asMatrix()));
Matrix resultMatrix = backwardMatrix.arrayTimes(forwardBelief.asMatrix());
result.updateFrom(resultMatrix);
result.normalize();
// System.out.println("fb :-normalized new backward message = "
// +result);
return result;
}
